Wheel unit for crossing obstacles

Abstract

The present application relates to a kind of wheel units for crossing obstacles, which keeps the shape change of the wheel minimum when driving on horizontal ground by using the principle that water droplets keep their shape by surface tension; when the obstacle hits the side surface of the wheel, the structure of the wheel is changed to easily cross the obstacle; in particular, in the case of crossing obstacles, obstacles can be effectively crossed by relative rotation and movement between adjacent unit blocks, and restored immediately after crossing obstacles.

Description

Technical Field

[0001] An exemplary embodiment of the present invention relates to a wheel unit for traversing obstacles. More specifically, an exemplary embodiment of the present invention relates to a wheel unit for traversing obstacles. The wheel unit employs a deformable structure utilizing the surface tension mechanism of water droplets. The wheel unit comprises multiple unit blocks, adjacent unit blocks being able to rotate and move relative to each other to travel on a level surface and easily traverse obstacles such as stairs. In particular, the wheel unit deforms stably when traversing obstacles. Background Technology

[0002] Recently, a large number of technologies have been developed related to wheels that can be driven while freely passing through obstacles or stairs.

[0003] In this type of obstacle-crossing wheel scenario, a typical approach involves either a variable stiffness structure where the wheel's stiffness is altered to overcome the obstacle, or a variable shape structure where the wheel's structure is significantly modified to overcome the obstacle. Here, the variable stiffness structure and the variable shape structure can be designed to be intricately interconnected.

[0004] In particular, regarding the latter variable shape structure, as disclosed in Korean Patent Publication No. 10-2174498, it is possible to overcome an obstacle by deforming or compressing the shape of some structures, such as those constituting a wheel, when in contact with an obstacle.

[0005] Furthermore, as disclosed in Korean Patent Publication No. 10-2014-0125166, a structure that passes through the ground by deforming its shape is also disclosed, wherein a portion of it is compressed according to the reaction force received from the ground when passing through the ground.

[0006] However, the problem with traditional wheels using this variable-shape structure for overcoming obstacles lies in the highly complex design of the wheel structure. Furthermore, in reality, traditional wheels cannot effectively overcome various obstacles, or require a considerable amount of time to change and retract the wheel structure during obstacle-crossing.

[0007] Furthermore, since the wheel structure is used to continuously traverse obstacles, stable deformation and structural recovery are very important. However, in the traditional integrated wheel structure, there are limitations in achieving this stable deformation and structural recovery by deforming only a part of the wheel structure. Summary of the Invention

[0008] Technical problems to be solved

[0009] The technical problem to be solved by the present invention is proposed based on the above content. The purpose of the present invention is to provide a wheel unit for overcoming obstacles. In this wheel unit, the principle of water droplets maintaining their shape through surface tension is utilized to minimize the change in wheel shape when traveling on a horizontal surface. When the side of the wheel collides with an obstacle, the structure is changed to easily overcome the corresponding obstacle. In particular, when overcoming obstacles, the relative rotation and movement between adjacent unit blocks can effectively overcome obstacles, and the wheel can be restored immediately after overcoming the obstacle.

[0010] Technical solution

[0011] A wheel unit according to one embodiment for achieving the above-described object of the present invention includes: a hub portion that rotates by receiving a rotational force; a plurality of unit blocks spaced at a predetermined distance from the hub portion and forming the shape of the wheel unit; and a support body configured to connect between the hub portion and the plurality of unit blocks, or to fill between the hub portion and the plurality of unit blocks, wherein when the wheel unit passes over a flat surface, the support body applies tension to the plurality of unit blocks in a direction toward the hub portion to cause the plurality of unit blocks to adhere to each other, wherein when the wheel unit traverses an obstacle, adjacent unit blocks among the plurality of unit blocks rotate or move relative to each other.

[0012] In one embodiment, the surface tension of a water droplet can be simulated by the adhesive forces between the plurality of unit blocks and the tension applied by the support.

[0013] In one embodiment, when the wheel unit traverses the obstacle, adjacent unit blocks that are in contact with the obstacle can rotate radially outward relative to each other, and at least a portion of adjacent unit blocks that are not in contact with the obstacle can rotate radially inward relative to each other.

[0014] In one embodiment, when the wheel unit traverses the obstacle, the outer surfaces of adjacent unit blocks that are in contact with the obstacle can form the same angle as the outer surface formed by the obstacle.

[0015] In one embodiment, when adjacent unit blocks rotate radially outward relative to each other, the adjacent unit blocks can remain in an adhered state, and when adjacent unit blocks rotate radially inward relative to each other, the adhered state of the adjacent unit blocks is released and the distance between the adjacent unit blocks is increased.

[0016] In one embodiment, each of the plurality of unit blocks may include: a body; a rotating portion disposed on one side of the body; a connecting portion disposed on the other side of the body and rotatably connected to the rotating portion of an adjacent unit block; and a pin that connects the connecting portion and the rotating portion of the adjacent unit block to allow it to rotate and move within a predetermined range.

[0017] In one embodiment, the rotating part may have a central opening extending in one direction, and the connecting part may have a connecting opening extending in one direction, the pin passing through both the connecting opening and the central opening of the adjacent unit block.

[0018] In one embodiment, the body may include: an inner surface facing the hub portion; an outer surface facing outward; a contact surface extending concavely between the inner surface and the outer surface; an end portion extending from the outer surface and protruding from the outer end of the contact surface; and an inclined protrusion extending from the inner surface of the body toward the other side and protruding obliquely in the direction toward the hub portion.

[0019] In one embodiment, each of the plurality of unit blocks may further include a groove formed between the joint and the outer surface of the body, wherein, when adjacent unit blocks rotate radially outward relative to each other, with the joint of the adjacent unit block adhered to the contact surface of the body of one unit block, the end of the body of one unit block is inserted into the groove of the adjacent unit block.

[0020] In one embodiment, the rotating portion may include a rotating block disposed at the contact surface of the body and a protrusion protruding radially inward from the rotating block, wherein when adjacent unit blocks rotate radially inward relative to each other, the distance between the center points of the joints of each of the adjacent unit blocks increases, and the movement of the protrusion of the rotating portion of one unit block is restricted by the inclined protrusion of the body of the other unit block.

[0021] In one embodiment, each of the plurality of unit blocks may include: a body forming an arcuate outer surface; and a connecting portion extending from the body and forming an insertion space into which the body of an adjacent unit block is inserted.

[0022] In one embodiment, the connection may include: a first connection surface extending from one side of the body; a second connection surface extending from the other side of the body and forming the insertion space with the first connection surface; and a contact surface connecting the first connection surface and the second connection surface, and having a recessed arcuate surface to contact the outer surface of the body of an adjacent unit block.

[0023] In one embodiment, each of the plurality of unit blocks may further include a recessed portion recessed between the body and the second connecting surface of the connecting portion, wherein, when adjacent unit blocks rotate radially outward relative to each other, with the body of the adjacent unit block adhering to the contact surface of the connecting portion of one unit block, the second connecting surface of the connecting portion of one unit block is inserted into the recessed portion of the adjacent unit block.

[0024] In one embodiment, when adjacent unit blocks rotate radially inward relative to each other, the contact surfaces of the body of one unit block and the joint of another adjacent unit block can be spaced apart and rotated, thus increasing the distance between the center points of the bodies of each of the adjacent unit blocks.

[0025] In one embodiment, the wheel unit may further include: an elastic line, fixed and extended by a fixing portion formed on the side surface of each of the plurality of unit blocks, and configured to apply an adhesive force between the plurality of unit blocks.

[0026] In one embodiment, when adjacent unit blocks rotate radially outward relative to each other and adjacent unit blocks rotate radially inward relative to each other, the adhesion state of the adjacent unit blocks can be released and the distance between the adjacent unit blocks can be increased.

[0027] In one embodiment, each of the plurality of unit blocks may include: a body having a protruding front surface portion and a recessed rear surface portion that engages with the front surface portion of an adjacent unit block; a fixing portion extending above the body; and a support portion protruding below the body.

[0028] In one embodiment, the support portion may include: a support frame extending in a direction parallel to the lower part of the body; and a support protrusion protruding in a direction perpendicular to the support frame.

[0029] In one embodiment, the support protrusion of one unit block in an adjacent unit block may be formed as a first support protrusion protruding from the center of the support frame, and the support protrusion of the other unit block may be formed as a pair of second support protrusions protruding from both sides of the support frame to form an insertion space for inserting into the first support protrusion.

[0030] In one embodiment, when the wheel unit traverses the obstacle, adjacent unit blocks that are in contact with the obstacle among the plurality of unit blocks can rotate radially outward relative to each other, such that the support protrusion contacts the obstacle and the bodies are spaced apart from each other.

[0031] In one embodiment, the fixing portion may include a contact surface and an end, the contact surface being configured to slide along the upper surface of the body of an adjacent unit block, the end being formed at the end of the contact surface, wherein the upper surface of the body and the fixing portion form a stepped portion, and when adjacent unit blocks rotate radially inward relative to each other, the movement of the end of the fixing portion of one unit block is restricted by the stepped portion of the adjacent unit block.

[0032] In one embodiment, each of the plurality of unit blocks may further include: a groove formed for a predetermined length on the front surface of the body; and a protrusion protruding from the rear surface of the body, wherein, when adjacent unit blocks rotate radially inward relative to each other, the movement of the protrusion of one unit block is restricted by the groove of the adjacent unit block.

[0033] In one embodiment, the hub portion may include a first hub unit and a second hub unit spaced apart from each other along the axial direction, and the support body includes multiple lines connecting the plurality of unit blocks to the first hub unit and the second hub unit, wherein the tension applied by the plurality of lines is adjusted when the distance between the first hub unit and the second hub unit is adjusted.

[0034] In one embodiment, the wheel unit may further include: a rotation drive configured to provide rotational force; a rotation unit connected to and rotating the rotation drive; a tension control unit configured to provide a sliding force along the axial direction; and a distance changing unit configured to provide the sliding force to at least one of the first hub unit and the second hub unit to adjust the distance between the first hub unit and the second hub unit, wherein the first hub unit and the second hub unit are located on the outer surface of the rotation unit and rotate integrally.

[0035] In one embodiment, the first hub unit may include: a first hub portion disposed on the outer surface of the rotating unit; and a first fixing portion formed along one side circumferential surface of the first hub portion, and fixing the plurality of lines to the first fixing portion. The second hub unit may include: a second hub portion disposed on the outer surface of the rotating unit; and a second fixing portion formed along the other side circumferential surface of the second hub portion, and fixing the plurality of lines to the second fixing portion.

[0036] In one embodiment, each of the plurality of lines may extend from one of the plurality of unit blocks, pass through the first fixing part and the second fixing part, and then extend again to one of the plurality of unit blocks.

[0037] In one embodiment, the rotating unit may include: a central frame connected to and rotating with the rotating drive unit; a main rotating unit fixed to the outside of the central frame; and

[0038] A stepped frame protrudes from the outer surface of the main rotating part and forms a stepped part with the main rotating part.

[0039] In one embodiment, the distance changing unit can provide the sliding force to the first hub unit, and the first hub unit slides along the axial direction on the main rotating part, while the position of the second hub unit is fixed by the stepped frame.

[0040] In one embodiment, the distance changing unit may include: a distance changing frame configured to receive the sliding force via the tension control section; and at least one extension rod extending from the distance changing frame along the axial direction and connected to the first hub unit or the second hub unit.

[0041] In one embodiment, the at least one extension rod may extend through the second hub unit, and the end of the at least one extension rod is fixed to the first hub unit, wherein the distance changing frame, the at least one extension rod, and the first hub unit slide along the axial direction by the sliding force.

[0042] In one embodiment, the wheel unit may further include a distance maintaining unit disposed between the tension control unit and the distance changing unit to maintain the distance between the rotation drive unit and the rotation unit.

[0043] In one embodiment, the distance maintaining unit may include: a transmission frame that slides by receiving the sliding force from the tension control unit; and a connecting frame that is fixed at a predetermined interval from the transmission frame and connected to the distance changing frame.

[0044] In one embodiment, the distance changing unit may further include a rotary bearing disposed between the connecting frame and the distance changing frame, wherein the distance changing frame rotates relative to the connecting frame due to the rotary bearing.

[0045] In one embodiment, the rotary bearing can rotate on an inner groove formed along the inner surface of the distance-changing frame, and the distance-changing frame is integrally moved along the axial direction with the connecting frame.

[0046] In one embodiment, the tension control unit may include: a tension control motor configured to generate a rotational force or a linear driving force; a deceleration unit configured to decelerate the driving force generated from the tension control motor and increase the rotational torque; and a sliding rod connected to the transmission frame and configured to convert the increased rotational torque into a sliding transmission force along the axial direction to provide the sliding transmission force to the transmission frame.

[0047] In one embodiment, the tension control unit may further include: a fixing frame extending radially outward from the deceleration unit to be connected to the rotary drive unit; and at least one sliding pin fixed to the fixing frame and extending along the axial direction toward the transmission frame.

[0048] In one embodiment, when the wheel unit passes over a flat surface, the distance between the first hub unit and the second hub unit can increase and the tension applied by the plurality of lines can increase; when the wheel unit traverses an obstacle, the distance between the first hub unit and the second hub unit can decrease and the tension applied by the plurality of lines can decrease.

[0049] In one embodiment, the wheel unit may further include: a controller configured to control the tension applied by the plurality of lines, wherein when the obstacle appears in front of the wheel unit, the controller reduces the distance between the first wheel hub unit and the second wheel hub unit to reduce the tension applied by the plurality of lines.

[0050] Beneficial effects

[0051] According to some exemplary embodiments of the present invention, based on the principle that water droplets maintain their appearance through surface tension, a force similar to the surface tension of water droplets is simulated by the tension applied by the support and the adhesive force between the unit blocks, so that the wheel unit maintains its overall shape and can effectively pass through the ground.

[0052] By applying the principle that the shape collapses when a force exceeding the critical deformation angle is applied to a water droplet, when a wheel unit comes into contact with an obstacle, it can effectively overcome the obstacle through the relative rotation and movement between adjacent unit blocks.

[0053] Here, through the structure of the unit blocks and the tension applied by the support after passing over an obstacle, the collapsed parts of the wheel unit can be easily restored to their original shape, thus maintaining the original shape of the wheel unit again. Therefore, the wheel unit can smoothly traverse obstacles and travel on the ground.

[0054] The overall deformation of the wheel unit can be controlled by adjusting the tension applied to the unit block. Therefore, the deformation of the wheel unit can be controlled depending on whether it is traveling on level ground or over obstacles, thus enabling effective ground driving. Consequently, optimized driving of the wheel unit can be achieved for various driving environments.

[0055] Here, the distance between the first and second wheel hub units can be controlled, thereby controlling the tension applied to the unit blocks. Therefore, the structural deformation of the wheel unit used for tension control can be eliminated, and tension can be easily and quickly adjusted while maintaining travel speed.

[0056] It should be understood that the beneficial effects of the present invention are not limited to the above description, but also include all effects that can be derived from the structure of the invention as described in the detailed description or claims. Attached Figure Description

[0057] Figure 1 This is a front view showing a wheel unit for overcoming obstacles according to a first embodiment of the present invention;

[0058] Figure 2 This is a schematic diagram illustrating the state of surface tension applied to a water droplet, and Figure 3 This is a schematic diagram illustrating how the contact angle of a water droplet changes with the magnitude of surface tension;

[0059] Figure 4 It is shown Figure 1 The wheel unit is viewed from the front of the ground, and 5 is... Figure 4 A schematic diagram comparing the state of the ground with the state of water droplets;

[0060] Figure 6 It is shown Figure 1 The main view of the wheel unit overcoming obstacles, and Figure 7 It is shown Figure 6 A diagram comparing the state of the water droplet as it overcomes obstacles;

[0061] Figure 8 and Figure 9 It is shown Figure 1 A 3D view of the unit block of the wheel unit;

[0062] Figure 10 It is shown Figure 8 A 3D diagram showing the state of a pair of unit blocks combined together;

[0063] Figure 11 , Figure 12 and Figure 13 It is shown Figure 6 A front view of the changing state of the unit block at contact point A when the wheel unit traverses an obstacle;

[0064] Figure 14 It is shown Figure 6 A three-dimensional diagram of the final change state of the unit block at contact part A when the wheel unit traverses an obstacle;

[0065] Figure 15 It is shown Figure 6 The front view of the final change state of the unit block at adjacent part B when the wheel unit traverses the obstacle;

[0066] Figure 16 This is a perspective view showing the tension controller and the first and second hub units according to a first embodiment of the present invention;

[0067] Figure 17 yes Figure 16 Side view;

[0068] Figure 18 It is shown Figure 16 A 3D view showing the second wheel hub unit removed;

[0069] Figure 19 It is shown in magnification Figure 16 A three-dimensional view of the connection status between the tension controller and the first and second hub units;

[0070] Figure 20 It is shown Figure 16 A three-dimensional diagram of the connection status between the distance changing unit and the distance unit of the tension controller;

[0071] Figure 21 It is a magnified perspective view showing the first and second hub units with multiple lines.

[0072] Figure 22 It is shown Figure 16 A perspective view of the state in which the first and second hub units are separated by a tension controller, and 23 is shown. Figure 16 A three-dimensional view of the approaching state between the first and second hub units via a tension controller;

[0073] Figure 24 A front view showing the state of the wheel unit for traversing obstacles according to a second embodiment of the present invention passing over the ground;

[0074] Figure 25 It is shown Figure 24 The main view of the wheel unit overcoming obstacles;

[0075] Figure 26 It is shown Figure 24 A three-dimensional diagram of the unit block of the wheel element, and Figure 27 It is shown Figure 26A 3D diagram showing the state of a pair of unit blocks combined together;

[0076] Figure 28 Show Figure 25 A front view of the changing state of the unit block at contact part A when the wheel unit traverses an obstacle;

[0077] Figure 29 Show Figure 25 A front view of the changing state of the unit block at adjacent part B when the wheel unit traverses an obstacle;

[0078] Figure 30 This is a front view showing the state of the wheel unit for overcoming obstacles according to a third embodiment of the present invention passing over the ground;

[0079] Figure 31 It is shown Figure 30 The main view of the wheel unit overcoming obstacles;

[0080] Figure 32 This is a schematic diagram illustrating the force transmission state when a traditional wheel unit overturns an obstacle, and Figure 33 It is shown Figure 30 A schematic diagram of the force transmission state when a wheel unit traverses an obstacle;

[0081] Figure 34 and Figure 35 It is shown Figure 31 A front view of the changing state of the unit block at contact part A when the wheel unit traverses an obstacle;

[0082] Figure 36 Show Figure 31 The front view of the changing state of the unit block at adjacent part B when the wheel unit traverses an obstacle, and Figure 37 It is shown Figure 36 The three-dimensional images of the unit blocks from different perspectives; and

[0083] Figure 38 This is a front view showing a wheel unit for overcoming obstacles according to a fourth embodiment of the present invention. Detailed Implementation

[0084] The invention will be described more fully below with reference to the accompanying drawings, in which exemplary embodiments of the invention are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0085] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to limit the invention. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well.

[0086] It will be further understood that when the terms “comprising,” “including,” and / or “having” are used in the specification, the presence of the said feature, number, step, operation, component, part, or combination thereof is specified, but the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof is not excluded.

[0087] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will be further understood that terms such as those defined in common dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant field, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0088] The wheel unit of an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0089] Figure 1 This is a front view showing a wheel unit for overcoming obstacles according to a first embodiment of the present invention. (Refer to...) Figure 1 The wheel unit 10 (hereinafter, wheel unit) for overcoming obstacles according to this embodiment includes multiple unit blocks 100, a support body 200, a hub portion 300 and an elastic line 400.

[0090] The hub portion 300 is located at the center of the wheel unit 10 and rotates about the central axis by receiving a rotational driving force from the rotational drive unit described below. The hub portion 300 rotates relative to the central axis of the wheel unit 10. Here, the hub portion 300 may be cylindrical.

[0091] Multiple unit blocks 100 are spaced apart from the hub portion 300 by a predetermined distance and arranged circumferentially. Each unit block 100 is adhered to each other to form a circle, thereby forming the overall shape of the wheel unit 10. Among the multiple unit blocks 100, adjacent unit blocks 100 can rotate and move relative to each other. Therefore, adjacent unit blocks can be brought close to or adhered to each other, or the state of being close to or adhered to each other can be released.

[0092] Each of the unit blocks 100 may have a predetermined thickness T, and may have along... Figure 1The predetermined width in the depth direction. Here, the thickness and width of each unit block 100 can be varied. However, the thickness T of each unit block 100 should be the minimum thickness sufficient to maintain the shape of the wheel unit 10 by the surface tension mechanism of the water molecules described below.

[0093] Each of the unit blocks 100 has the same shape, and the shape will be described in more detail below.

[0094] In this exemplary embodiment, the elastic line 400 extends along the outer side of the plurality of unit blocks 100 and provides an adhesive force to bring the plurality of unit blocks 100 closer together. Here, the elastic line 400 is an elastic body with a predetermined tension, and the elastic force of the elastic line 400 can vary. In addition, according to the exemplary embodiment, the elastic line 400 may not be necessary and may be omitted.

[0095] Additionally, as described below, the elastic line 400 extends along the sides 114 and 115 of the unit block, thus the elastic line 400 is generally connected in a circular shape. That is, the elastic line 400 fixes the unit blocks 100 together in a circular shape, so that the unit blocks 100 receive forces toward the hub portion 300, thus providing adhesive forces for the multiple unit blocks 100 to adhere to each other.

[0096] The elastic line 400 provides a predetermined elastic force to maintain an overall circular shape, but the shape of the elastic line 400 can be deformed into a variable state as the relative bonding state between the unit blocks 100 changes. That is, although the elastic line 400 provides a predetermined elastic force, it does not necessarily provide enough elastic force to maintain the overall adhesive force of the unit blocks 100, so the extension state of the elastic line 400 can also change when the bonding state between the unit blocks 100 changes to overcome an obstacle.

[0097] The support 200 connects the hub portion 300 to a plurality of unit blocks 100, and in this exemplary embodiment, the support 200 may be a plurality of wires with a predetermined tension. However, the support 200 may not be limited to wires, and the support 200 may be any object that can connect the hub portion 300 to the plurality of unit blocks 100 and apply tension.

[0098] The support 200 can be connected one by one to each of the plurality of unit blocks 100, thereby applying a predetermined tension to each of the plurality of unit blocks 100, but is not limited thereto. When taking into account that adjacent unit blocks 100 are in a state of being joined together, the support 200 can also be connected only to the unit blocks 100 that are separated by a predetermined interval among the plurality of unit blocks 100.

[0099] The support 200 has a predetermined tension, thereby applying a pulling force, i.e., tension, between the hub portion 300 and the plurality of unit blocks 100. Therefore, the position of the unit blocks 100 can be maintained, and the unit blocks 100 can be prevented from detaching outward.

[0100] In this embodiment, except for the case where the wheel unit 10 passes through an obstacle as described later, the support 200 applies a constant tension to all unit blocks 100 as a whole, so that the attraction between water molecules inside the water droplet when the droplet maintains its shape is formed into the attraction inside the wheel unit 10.

[0101] Therefore, by adjusting the tension provided from the support 200 in various ways, the state maintaining the shape of the wheel unit 10 can be changed. That is, when a large tension is applied to the support 200, a state of high surface tension of water molecules is simulated among the multiple unit blocks 100, thereby strengthening the state in which the wheel unit 10 as a whole maintains its circular shape. In contrast, as the tension is relatively reduced, a state of reduced surface tension is simulated, so the wheel unit 10 as a whole can be realized in a state in which its surface deforms according to the shape of the ground or obstacle.

[0102] The following will combine Figure 2 and Figure 3 Describe in detail how wheel unit 10 simulates the surface tension of a water droplet. Figure 2 This is a schematic diagram illustrating the surface tension applied to a water droplet, and Figure 3 This is a schematic diagram illustrating how the contact angle of a water droplet changes according to the magnitude of surface tension.

[0103] When a water droplet remains spherical due to surface tension upon contact with a surface, the water molecules inside the droplet experience the same forces from the surrounding molecules. However, the water molecules on the surface experience forces only in specific directions. The equilibrium state of the forces inside the water molecules and on the surface is as follows: Figure 2 As shown, when the attractive force between water molecules increases, the inward pull increases, and with the increase in surface tension, the spherical shape of the water molecules is maintained more stably.

[0104] That is, such as Figure 3 As shown, as the attractive force between water molecules decreases, the surface tension of the surface decreases, and therefore the contact angle θ of the water droplet decreases. In other words, as the attractive force between water molecules in the water droplet increases, the surface tension increases, and therefore the contact angle of the water droplet increases, forming a water droplet that is closer to a spherical shape.

[0105] Therefore, in the case of the wheel unit 10 of this exemplary embodiment, the surface tension generated by the application of the attractive force between water molecules is simulated. Here, the surface tension when a water droplet maintains its shape can be effectively simulated by the tension provided by the support 200 and the adhesive force between the elastic line 400 and the plurality of unit blocks 100.

[0106] Finally, the wheel unit 10 simulates maintaining the appearance of the water droplet by applying a surface tension mechanism through the placement of incompressible or difficult-to-compress molecules above a certain level on the outer surface of the droplet. Therefore, the surface tension mechanism can be applied through the aforementioned connection structure of multiple unit blocks 100 and the support 200.

[0107] In the following text, refer to Figure 4 and Figure 5 This will describe how the shape maintenance state based on the surface tension of the water droplet is applied to the wheel unit 10 of this exemplary embodiment. Figure 4 It is shown Figure 1 The wheel unit passes through the main view of the ground state, and Figure 5 yes Figure 4 The diagram shows a comparison between the state of the ground and the state of the water droplets.

[0108] Reference Figure 4 When the wheel unit 10 passes over the flat ground 1, due to the structure of the unit blocks described below, the multiple unit blocks 100 are tightly connected to each other, and at the same time, the support body 200 applies tension to the multiple unit blocks 100 in the direction toward the hub portion 300. In addition, as described above, the elastic line 400 also applies tension to the multiple unit blocks 100 in the direction toward the hub portion 300.

[0109] In this state, when wheel unit 10 passes over ground 1, as... Figure 4 As shown, although the lower side of the wheel unit 10 in contact with the ground 1 may deform in a slightly compressed manner, the overall appearance of the wheel unit 10 can still be maintained. Here, the degree of compression can be adjusted according to the magnitude of the tension applied by the support 200, as described above. Figure 3 As described in [the text].

[0110] like Figure 5 As shown, the state of wheel unit 10 passing over ground 1 can be simulated as a water droplet in contact with the ground. Here, if the entire wheel unit 10 is simulated as a water droplet, it can be interpreted as wheel unit 10 passing over ground 1 while maintaining contact with ground 1, and having a predetermined contact angle θ with ground 1. Here, the contact angle θ should remain obtuse, and as the contact angle increases, the shape of wheel unit 10 can have a shape closer to a circle or a sphere.

[0111] Then, refer to Figure 6 and Figure 7 This will explain how the state of a water droplet losing its shape due to the collapse of its surface tension applies to the wheel unit 10 of this exemplary embodiment. Figure 6 It is shown Figure 1 The main view of the wheel unit overcoming obstacles, and Figure 7 yes Figure 6A diagram comparing the state of overcoming obstacles with the state of a water droplet.

[0112] Reference Figure 6 When one side of the wheel unit 10 collides with an obstacle 6, such as a step, located on the ground 1, the wheel unit 10 begins to deform at the point of impact. That is, referring to... Figure 7 The collision simulation of the water droplet collision state shown shows that when the wheel unit 10 collides with the obstacle 6, the contact angle θ of the wheel unit 10 at the contact portion A with the obstacle 6 suddenly exceeds the so-called deformation critical angle (e.g., 180°).

[0113] Thus, at the instant the deformation critical angle is exceeded, the shape of wheel unit 10 also collapses, while the shape of obstacle 6 is reflected at contact portion A, similar to the collapse of a water droplet shape due to rapid large deformation. That is, the combined state changes through the relative rotation and movement between adjacent unit blocks 100. Here, since the hub portion 300 rotates continuously, even if the shape of unit block 100 is in a collapsed state, wheel unit 10 tumbles over obstacle 6, while hub portion 300 rotates around contact portion A.

[0114] As described above, in this embodiment, if the wheel unit 10 simply passes over a flat ground 1, the wheel unit 10 maintains its overall circular or spherical shape while passing over the ground 1, just as a water droplet maintains its shape through surface tension. However, in the event of a collision with an obstacle 6, the combined state of the unit block 100 deforms in a localized area, and the external shape of the obstacle 6 is reflected around the collision location, thereby causing the wheel unit 10 to roll over the obstacle 6.

[0115] Here, since the adjacent unit blocks 100 at the contact part A maintain their outer surfaces in contact with the outer surfaces of the obstacle 6 and cross the obstacle 6, the adjacent unit blocks 100 rotate relative to each other in the direction of the obstacle 6, that is, radially outward and deform into a bent state.

[0116] In contrast, at an adjacent portion B located a certain distance forward or backward from the contact portion A, the distance between the outer surfaces of the relatively adjacent unit blocks 100 increases while the distance between their inner surfaces decreases to compensate for the larger deformation of the outer surfaces of the unit blocks 100 adjacent to each other at the contact portion A. Therefore, at the adjacent portion B, unlike at the contact portion A, the adjacent unit blocks 100 rotate relative to each other and deform into a bent state in the direction toward the hub portion 300, i.e., in the radially inward direction.

[0117] In other words, the relative deformation states of adjacent unit blocks 100 at the contact portion A and the adjacent portion B are realized in different ways, and this will be further explained in detail below after describing the detailed structure of a single unit block 100.

[0118] In the following text, refer to Figure 8 and Figure 9 This describes the detailed structure of each of the multiple unit blocks 100 and the connection status between adjacent unit blocks 100. Figure 8 and Figure 9 It is shown Figure 1 A three-dimensional view of the unit block of the wheel unit.

[0119] Each of the multiple unit blocks 100 includes a body 110, a joint 120, a groove 130, a rotating part 140, and a pin 150.

[0120] The main body 110 forms the main body of the unit block 100 and can generally have a quadrilateral block shape. A rotating part 140 is attached to the front side of the main body 110, and a pair of connecting parts 120 are attached to the rear side of the main body 110. For ease of explanation, the right side of the main body 110 in the figure is referred to as the front side, and the left side as the rear side, but this is not a limitation. The main body 110 has a predetermined width (length along the Y direction in the figure), and the width of the main body 110 can be designed to be various widths.

[0121] Specifically, the main body 110 includes: an inner surface 111 facing the hub portion 300; an outer surface 117 facing the obstacle 6 or the ground 1 in a direction opposite to the inner surface 111; and a pair of side surfaces 114 and 115 connecting the outer surface 117 and the inner surface 111.

[0122] Furthermore, the main body 110 includes an inclined protrusion 112, a contact surface 113, and an end portion 116. The inclined protrusion 112 extends rearward from the inner surface 111 and forms a surface that protrudes obliquely toward the hub portion 300. That is, compared to the inner surface 111, the inclined protrusion 112 protrudes more toward the hub portion 300, and the protrusion gradually becomes oblique as it moves away from the inner surface 111. The contact surface 113 is a surface extending between the inner surface 111 and the outer surface 117, and has a concave curved surface shape that corresponds to the outer surface of the cylindrical rotating portion 140 described later. The end portion 116 is formed at the outermost end of the contact surface 113, i.e., the portion where the contact surface 113 connects to the outer surface 117, and the end portion 116 has a sharp protruding shape as shown in the figure.

[0123] The joint portions 120 extend from both sides of the rear end of the main body portion 110 and are formed as a pair. The pair of joint portions 120 are formed in a symmetrical shape, so only for... Figure 8 and Figure 9 The joint 120 on one side shown will be described.

[0124] One side of the joint portion 120 extends integrally from the side surface 114 of the main body 110 toward the rear end, and the joint portion 120 is integrally formed with the main body 110. Here, the joint portion 120 has a predetermined width W1, and the width W1 of the joint portion 120 may be smaller than the width W2 of the inclined protrusion 112. Here, the sum of the widths of the pair of joint portions 120, 2*W1, may also be smaller than the width W2 of the inclined protrusion 112.

[0125] The connecting portion 120 includes a cylindrical connecting block 121 with a width W1 extending from one side of the main body 110, as well as an upper fixing portion 123 and a lower fixing portion 124. A connecting opening 122 is formed through the center of the connecting block 121, and a pin 150 is inserted into the connecting opening 122. The length of the connecting opening 122 along the height direction (Z direction) can be substantially the same as the diameter of the pin 150 (here, its length needs to be a predetermined amount larger than the diameter of the pin 150 so that the pin 150 inserted into the connecting opening 122 can rotate relative to the connecting opening 122), however, the length of the connecting opening 122 along the length direction (X direction) is ( Figure 10 L1 in the figure needs to be larger than the diameter of pin 15. Therefore, with pin 150 inserted into the engagement opening 122, the position of pin 150 can be restricted in the height direction, but can move freely within a predetermined range in the length direction.

[0126] The upper fixing portion 123 and the lower fixing portion 124 protrude from the side of the connecting block 121. The upper fixing portion 123 is provided above the connecting opening 122 and protrudes in a block shape, and the lower fixing portion 124 is provided below the connecting opening 122 and protrudes in a block shape. A fixing space 125 is formed between the upper fixing portion 123 and the lower fixing portion 124, and the elastic line 400 can be fixed by extending through the fixing space 125. Considering the thickness of the elastic line 400, the spacing of the fixing space 125 can be formed differently. That is, the elastic line 400 is fixed along the fixing space 125 and extends as a whole over the multiple unit blocks 100, so the elastic force of the elastic line 400 can be provided to the multiple unit blocks 100 toward the hub portion 300, and the adhesive force between the multiple unit blocks 100 can be provided.

[0127] A groove 130 is formed on the lower side where the connecting portion 120 connects to the main body 110. Specifically, the groove 130 is equivalent to the portion where the outer surface of the connecting block 121 connects to the outer surface 117 of the main body 110. Here, for ease of description, it is described as "lower side" based on the accompanying drawings, but the unit block as a whole can also be in an upside-down state, so "lower side" can also be "upper side" depending on the situation. However, in the following text, for ease of explanation, it is described as "lower side" based on the accompanying drawings, and further, the "lower side" is substantially the same as the "outer side" facing an obstacle or the ground.

[0128] Specifically, the groove portion 130 includes an extending curved surface 131 and an extending vertical surface 132. The extending curved surface 131 extends from the outer peripheral surface of the connecting block 121 (the outer peripheral surface of the cylinder), and its curvature is the same as that of the outer peripheral surface of the connecting block 121. The extending vertical surface 132 extends from the edge of the outer surface 117 of the body 110 to form a flat surface. Here, the extending vertical surface 132 can extend and intersect with the outer surface 117, and the angle of intersection can vary but can be perpendicular to each other. Therefore, as the extending curved surface 131 and the extending vertical surface 132 extend with different curvatures, a supporting groove 133 is formed between the extending curved surface 131 and the extending vertical surface 132, and the concave shape of the supporting groove 133 can be pointed.

[0129] The rotating part 140 is formed at the front end of the main body 110 and is integrally formed with the main body 110. The rotating part 140 includes a rotating block 141 and a protrusion 144.

[0130] The rotating block 141 is cylindrical in shape, and its overall width is substantially the same as the overall width W2 of the inclined protrusion 112. The rotating block 141 has a rotating outer surface 143, the curvature of which is substantially the same as the curvature of the contact surface 113, so that the rotating outer surface 143 of the rotating block 141 is partially adhered to the contact surface 113.

[0131] Here, the width W2 of the rotating block 141 is less than the overall width W1+W1+W2 of the main body 110. Therefore, the width of the rotating block 141 is the overall width of the main body 110 minus the width of the two side joints 120. Thus, contact surfaces 113 are formed on both sides of the rotating block 141, exposing side spaces 151 to the outside, and the joints 120 of adjacent unit blocks are located on the side spaces 151.

[0132] Furthermore, a central opening 142 is formed at the center of the rotating block 141, and the pin 150, described later, is inserted through the central opening 142. Here, the shape of the central opening 142 can be substantially the same as the shape of the aforementioned connecting opening 122. That is, the length of the central opening 142 along the height direction (Z direction) can be substantially the same as the diameter of the pin 150 (similarly, its length needs to be a predetermined amount larger than the diameter of the pin 150 so that the pin 150 inserted into the central opening 142 can rotate relative to the central opening 142), however, the length of the central opening 142 along the length direction (X direction)... Figure 10 L2 in the middle needs to be larger than the diameter of pin 15. Therefore, with pin 150 inserted into the central opening 142, the position of pin 150 can be restricted in the height direction, but can move freely within a predetermined range in the length direction.

[0133] The protrusion 144 protrudes radially inward from the rotating block 141, i.e., toward the hub portion 300, and extends from the inner surface 111 of the main body 110. Here, the overall width of the protrusion 144 is the same as the width of the rotating block 141, and the width of the cross-section of the protrusion 144 decreases radially inward. That is, the cross-sectional shape of the protrusion 144 (the cross-sectional shape along the XZ plane) can be triangular in shape overall.

[0134] However, when the surface is formed by the protrusion 144, the surface extending from the inner surface 111 can be a flat shape, but the opposite surface, namely the support surface 145 which is connected to the rotating outer surface 143, can be an inwardly concave curved surface. That is, the support surface 145 can be a curved surface extending with a concave shape and a predetermined curvature.

[0135] The pin 150 has a pin shape with a predetermined diameter extending along the Y direction. As described below, the pin 150 passes through both the central opening 142 and the engagement opening 122 of a pair of engagement portions 120 of adjacent unit blocks. Therefore, a pair of adjacent unit blocks 100 are engaged with each other by the pin 150.

[0136] A unit block 100 having the shape and structure described above is joined to another adjacent unit block 100, as shown below. Figure 10 This describes the combination state of a pair of adjacent unit blocks 100. Figure 10 It is shown Figure 8 A 3D diagram showing the state of a pair of unit blocks combined together.

[0137] Reference Figure 10 Adjacent unit blocks 100 extend along the X-axis and are joined together. That is, in this embodiment, adjacent unit blocks 100 basically maintain the joined state shown in the figure, and the unit blocks 100 can overcome obstacles by relative rotation and movement, thereby maintaining a stable joined state when overcoming obstacles.

[0138] Specifically, the pin 150, extending through the central opening 142 of the first unit block 100a (for ease of explanation, the pair of unit blocks are distinguished as the first unit block 100a and the second unit block 100b), also passes through the joint openings 122 formed at a pair of joint portions 120 of adjacent second unit blocks 100b. Furthermore, the pair of joint portions 120 of the second unit blocks 100b are located in a pair of side spaces 151 formed in the first unit block 100a. Therefore, the pair of adjacent unit blocks 100a and 100b are joined together by the pin 150, with the rotating portion 140 located at the center and the pair of joint portions 120 located on both sides.

[0139] Furthermore, although not illustrated, the unit blocks can be joined on the other side of the first unit block 100a in the same joining state as described above, and the unit blocks can be joined on the other side of the second unit block 100b in the same joining state as described above, so that the multiple unit blocks are connected in a joined state as a whole.

[0140] In addition, such as Figure 10 As shown, when the first unit block 100a and the second unit block 100b are horizontally joined together along the X-axis, the pin 150 can move freely along the X-axis within a predetermined distance due to the shape of the central opening 142 and the shape of the joining opening 122. Therefore, the interval between the first unit block 100a and the second unit block 100b can also be freely changed within the range of movement of the pin 150, thus performing the effective operation of overcoming obstacle 6 as described below.

[0141] Figure 11 , Figure 12 and Figure 13 It is shown Figure 6 A front view showing the change of the unit block at contact portion A when the wheel unit traverses an obstacle. Here, although not shown in the figure, the obstacle 6 is in contact with the underside of the first unit block 100a and the second unit block 100b.

[0142] Reference Figure 11 , Figure 12 and Figure 13 When the wheel unit 10 according to this embodiment traverses the obstacle 6, the engagement state changes, causing the adjacent unit blocks 100 at the contact portion A to engage and simultaneously bend radially outward, that is, bend in the direction in which their outer surfaces 117 approach each other. Here, the outer surfaces 117 of the adjacent unit blocks 100 that contact the obstacle 6 at the contact portion A can approach each other and form an angle that is the same as the angle formed by the outer surface of the obstacle 6.

[0143] According to the change in the bonding state as described above, when the contact surface 113 of the first unit block 100a is in contact with the outer surface of the bonding block 121 of the second unit block 100b, the end 116 of the first unit block 100a moves along the extended curved surface 131 of the second unit block 100b and finally inserts into the support groove 133. Here, the curvature of the extended curved surface 131 is substantially the same as the curvature of each of the bonding block 121 and the contact surface 113, so that the end 116, which is the outermost end of the contact surface 113, is smoothly inserted into the support groove 133.

[0144] Here, since the position of pin 150 can be freely changed within a predetermined range, the relative positions of adjacent first unit blocks 100a and second unit blocks 100b can also be changed. Therefore, by changing the relative positions of the first unit blocks 100a and second unit blocks 100b as described above, the optimal relative position according to the shape of obstacle 6 can be ensured. Here, when the adjacent first unit blocks 100a and second unit blocks 100b extend horizontally, as the extension angle of the first unit blocks 100a and second unit blocks 100b decreases (i.e., from 180° to 90°), the angle between the length direction of the central opening 142 and the length direction of the connecting opening 122 also decreases, thus relatively reducing the movable range of pin 150. Therefore, when the first unit blocks 100a and second unit blocks 100b form a right angle (90°), the movement of pin 150 is restricted, and pin 150 is fixed at the central opening 142 and the connecting opening 122 in a state where pin 150 cannot move. The fixed state of pin 150 is as follows: Figure 14 As shown.

[0145] In the following text, reference will be made to Figure 14 This describes the final state in which the unit blocks 100 are adjacent to each other at the contact part A when the wheel unit 10 is overcoming the obstacle 6. Figure 14 It is shown Figure 6 A three-dimensional diagram of the final change state of the unit block at contact part A when the wheel unit traverses an obstacle.

[0146] Typically, in order to overcome obstacle 6, unit block 100 needs to be fixed at contact point P where it contacts obstacle 6. Figure 14 (P) and unit block 100 rotates around contact point P. This rotation makes it easy to overcome obstacle 6.

[0147] In this regard, as referred to above Figure 11 , Figure 12 and Figure 13 As described, the first unit block 100a and the second unit block 100b, which are adjacent to each other, rotate relative to each other in a radially outward bending direction when they come into contact with the obstacle 6, and finally... Figure 14The first unit block 100a and the second unit block 100b are positioned as shown. Specifically, the end 116 of the first unit block 100a moves along the extended surface 131 of the second unit block 100b and eventually inserts into the support groove 133. Therefore, the outer surfaces 117 of the first unit block 100a and the second unit block 100b are perpendicular to each other, and the outer surfaces 117 contact the outer surface of the obstacle 6. For example, when the obstacle 6 includes a vertically formed surface like a step, the outer surfaces 117 of adjacent first unit blocks 100a and second unit blocks 100b are positioned and fixed on the vertically formed surface of the obstacle 6, and then the outer surfaces 117 provide contact points for the rotation of the wheel unit 10.

[0148] However, it is not necessary for the outer surfaces 117 of adjacent unit blocks to contact both vertical surfaces of the vertical obstacle 6, and the contact state can be variable, for example, considering the sequential contact of the two vertical surfaces of the obstacle 6. Furthermore, when the two surfaces formed by the obstacle 6 are not perpendicular, the outer surfaces 117 of adjacent unit blocks 100 may not be perpendicular, and in this case, the end 116 of the first unit block 100a can be positioned inside the support groove 133 of the second unit block 100b with only a suitable degree of insertion.

[0149] However, since the outer surfaces 117 of the adjacent unit blocks 100 remain in contact with the obstacle 6 at the contact point P under any circumstances, if a rotational force is applied to the wheel unit 10 in one direction as a whole, the adjacent unit blocks 100 rotate around the contact point P to overturn the obstacle 6.

[0150] Furthermore, as described above, in order to traverse the obstacle 6 around the contact point P, the inner side of the unit block 100 in contact with the obstacle 6 should be freely deformable. In this example embodiment, as shown, the first unit block 100a and the second unit block 100b, which are adjacent to each other, can rotate freely relative to each other along the inner surface 111 in a direction away from each other, until the end 116 of the first unit block 100a is restricted from further movement by the support groove 113 of the second unit block 100b. Therefore, free deformation of the inner side of the unit block 100 in contact with the obstacle 6 can be achieved.

[0151] With adjacent first unit blocks 100a and second unit blocks 100b tightly adhered to each other, the distance between the center C of the joint portion 120 of the first unit block 100a and the center C′ of the joint portion 120 of the second unit block 100b remains constant and unchanged. As described above, this is because the joint opening 122 and the center opening 142 extend in directions that intersect each other, thereby limiting the range of movement of the pin 150 located therein. Therefore, the unit block 100 in contact with the obstacle 6 maintains a relatively stable posture and can stably absorb the external force generated when in contact with the obstacle 6, thereby allowing it to overcome the obstacle 6.

[0152] Here, the adhesion between unit blocks can be maintained by the elastic line 400 passing through the fixed space 125 and connecting the adjacent unit blocks 100, thereby allowing the obstacle 6 to be steadily traversed.

[0153] Therefore, when the interconnected unit blocks come into contact with an obstacle, the inner side of the unit block rotates freely, while the outer side rotates around the contact point P and remains fixed. This avoids problems such as the wheel unit 10 being bounced up when it comes into contact with an obstacle, and effectively absorbs the external force generated by contact with the obstacle, thus allowing for efficient obstacle clearance.

[0154] Then, Figure 15 It is shown Figure 6 The front view of the final change state of the unit blocks at the adjacent part B when the wheel unit 10 crosses the obstacle 6. In the state where the wheel unit 10 crosses the obstacle 6, unlike the state where the adjacent unit blocks 100 are in close contact and rotating relative to each other in the contact part A, the relative positions of the adjacent unit blocks 100 change in a different way at the adjacent part B.

[0155] Reference Figure 15 At adjacent part B, the exterior of the third unit block 100c and the fourth unit block 100d, which are adjacent to each other, are deformed away from each other due to tensile force, but their interiors are deformed to move closer to each other due to compressive force. Therefore, the third unit block 100c and the fourth unit block 100d, which are adhered to each other, can rotate relative to each other in a direction opposite to the relative rotation in contact part A.

[0156] That is, the adjacent third unit block 100c and fourth unit block 100d rotate radially inward, i.e., in the direction toward the hub portion 300, so that the end 116 of the third unit block 100c moves along the circumferential surface of the connecting block 121 in a direction away from the support groove 133 of the fourth unit block 100d adjacent to the third unit block 100c. In addition, the support surface 145 of the third unit block 100c moves toward the inclined protrusion 112 of the fourth unit block 100d.

[0157] Here, the close contact between the adjacent third unit block 100c and fourth unit block 100d is released, and the distance between the center of the joint portion 120 of the third unit block 100c and the center of the joint portion 120 of the fourth unit block 100d increases. That is, the distance between the rotating portion 140 and the joint portion 120 of the adjacent third unit block 100c and fourth unit block 100d increases to its maximum. However, the rotating portion 140 and the joint portion 120 of the third unit block 100c and fourth unit block 100d are kept engaged by the pin 150, such that the pin 150 is located at the right end of the central opening 142 of the third unit block 100c and at the left end of the joint opening 122 of the fourth unit block 100d, thereby limiting the increase in the distance between the third unit block 100c and fourth unit block 100d.

[0158] Furthermore, even if the adjacent third unit block 100c and fourth unit block 100d rotate radially inward, the inclined protrusion 112 of the fourth unit block 100d prevents further movement of the support surface 145 of the third unit block 100c. Therefore, the amount of rotation of the adjacent third unit block 100c and fourth unit block 100d can be limited. Thus, imbalances or unstable disconnections between unit blocks due to excessive segmentation and rotation are unlikely to occur.

[0159] Therefore, even if the outer surfaces 117 of adjacent third unit blocks 100c and fourth unit blocks 100d are spaced apart and separated from each other, it is possible to prevent them from separating completely from each other in their contact state. In particular, in this example embodiment, since the elastic line 400 maintains the adhesion between adjacent unit blocks, the surfaces 117 of adjacent third unit blocks 100c and fourth unit blocks 100d will not completely separate from each other, thus preventing the overall appearance of the wheel unit 10 from collapsing.

[0160] Therefore, at adjacent portion B, the tensile force applied to the outside of unit block 100 is absorbed by the elastic line 400, and the compressive force applied to the inside of unit block 100 is absorbed by the support surface 145 and the inclined protrusion 112. Furthermore, during this process, the engagement state between unit blocks 100 is stably maintained by the pin 150. Therefore, there is no displacement of unit blocks 100 or irregular change in the relative positions between unit blocks 100, and the overall shape of the wheel unit 10 can remain unchanged.

[0161] Therefore, when the wheel unit 10 crosses the obstacle 6, the adjacent unit blocks maintain different bonding relationships at the contact part A and the adjacent part B and change their relative positions, but can stably cross the obstacle without the overall shape of the wheel unit 10 collapsing.

[0162] In particular, due to the specific structure of the unit block 100 according to this example embodiment, a stable connection can be maintained during obstacle crossing regardless of the position of the unit block 100 in the contact portion A or the adjacent portion B. Adjacent unit blocks 100 can be in close contact with each other or freely separated, and changes in relative position can be further restricted. Therefore, the wheel unit 10 can effectively cross obstacles.

[0163] According to the example embodiment described above, based on the principle that water droplets maintain their appearance through surface tension, a force similar to the surface tension of water droplets is simulated by the tension applied by the support and the adhesive force between the unit blocks applied by the elastic line, so that the wheel unit maintains its overall shape and passes through the ground effectively.

[0164] In addition, by applying the principle that the shape of a water droplet collapses when a force exceeding the critical deformation angle is applied to it, when the wheel unit comes into contact with an obstacle, the unit blocks at the contact point adhere to each other and the spacing is fixed, while the adjacent unit blocks adjacent to the contact point are released from the adhesion state and the spacing is increased, thereby effectively overcoming obstacles.

[0165] Here, even if the adhesion between unit blocks is released and collapses in adjacent parts, the adjacent unit blocks are still connected by pins. Therefore, it is possible to overcome obstacles while maintaining a stable connection between unit blocks and stably maintaining the overall shape of the wheel unit.

[0166] Therefore, even if the adhesion between unit blocks is released at adjacent parts, a stable connection between the unit blocks can be maintained. The elastic force provided by the elastic line can easily restore the state of the unit blocks that have been released from close contact, thus maintaining the original shape of the wheel unit again. Therefore, obstacle crossing and movement on the ground can be easily achieved.

[0167] That is, each of the unit blocks includes a rotating part with a central opening and a connecting part with a connecting opening, so that adjacent unit blocks are stably connected to each other by pins, thereby maintaining stable and efficient driving when crossing obstacles or driving on the ground.

[0168] Furthermore, the elastic lines fix adjacent unit blocks together with a predetermined elastic force, so that even if the force is concentrated in a specific unit block, the force can be distributed as a whole, and the degree of division between the segmented unit blocks can be limited within a certain range. Therefore, the wheel structure can effectively overcome obstacles and maintain stability.

[0169] In an example embodiment, the wheel unit 10 may further include a tension control section configured to control the tension applied by the support 200.

[0170] Figure 16This is a perspective view showing a tension controller, a first hub unit, and a second hub unit according to a first embodiment of the present invention. Figure 17 It is shown Figure 16 Side view of the tension controller and the first and second hub units.

[0171] Reference Figure 16 and Figure 17 According to this example embodiment, the wheel unit 10 further includes a rotation drive unit 1100, a tension control unit 1200, a distance holding unit 1300, a distance changing unit 1400, and a rotation unit 1500, all serving as tension control units. Here, the hub portion 300 includes a first hub unit 1600 and a second hub unit 1700 spaced apart from each other along the axial direction, i.e., the Y-axis. Here, the distance between the first hub unit 1600 and the second hub unit 1700 is adjusted to control the tension applied by the support body 200.

[0172] First, the rotary drive unit 1100 generates and provides rotational force, and includes a rotary motor housing 1110, a rotary motor space 1120, a rotary shaft 1130, and a rotary shaft housing 1140.

[0173] A rotary motor space 1120 is formed inside the rotary motor housing 1110, and a rotary motor (not shown) that generates rotational force can be disposed in the rotary motor space 1120. Here, the rotary motor generates rotational force with the Y-axis as the rotation center axis, and provides the rotational force thus generated to the rotary shaft 1130. As a result, the rotary shaft 1130 rotates with the Y-axis as the rotation center axis and provides rotational force to the rotary unit 1500.

[0174] In addition, the rotating shaft housing 1140 is disposed outside the rotating shaft 1130, and the rotating shaft 1130 is disposed inside the rotating shaft housing 1140. The rotating motor housing 1110 and the rotating shaft housing 1140 can respectively house the rotating motor and the rotating shaft 1130 inside, and the shape or structure of the rotating motor housing 1110 and the rotating shaft housing 1140 is not limited to the figures shown.

[0175] The rotating shaft 1130 passes through the fixture 1230, the distance holding unit 1300, and the distance changing unit 1400 (described later) and is connected to the rotating unit 1500. Each of the fixture 1230, the distance holding unit 1300, and the distance changing unit 1400 includes an internal opening through which the rotating shaft 1130 passes, so as not to restrict or limit the rotation of the rotating shaft 1130.

[0176] The tension control unit 1200 provides a sliding driving force or sliding transmission force along the Y-axis direction, and includes a tension control motor 1210, a reduction unit 1220, a fixed frame 1230, a sliding rod 1240, and a sliding pin 1250.

[0177] The tension control motor 1210 generates a driving force to provide a sliding driving force along the Y-axis direction, and may be a rotary motor that generates a rotational force. Therefore, the rotational force generated by the tension control motor 1210 is provided to the reduction unit 1220 through the drive transmission shaft 1211.

[0178] In contrast, the tension control motor 1210 can also be a linear motor that generates a linear driving force along the Y-axis. When the tension control motor 1210 is a linear motor, the drive transmission shaft 1211 can provide a driving force along the Y-axis to the reduction unit 1220.

[0179] The reduction unit 1220 contains a reduction gear 1221, which reduces the rotational or linear driving force provided by the drive transmission shaft 1211 to increase the rotational torque. The increased rotational torque by the reduction gear 1221 is provided to the sliding rod 1240, which is connected to the reduction gear 1221 via gear engagement. Here, gear teeth 1241 are formed on the upper surface of the sliding rod 1240, and the reduction gear 1221 meshes with the gear teeth 1241 to perform a gear engagement similar to a worm gear. Therefore, the rotational force of the reduction gear 1221 with a large torque can be converted into a sliding transmission force of the sliding rod 1240 along the Y-axis direction.

[0180] As described above, the rotational force or linear transmission driving force generated by the tension control motor 1210 is converted into a higher torque by the deceleration unit 1220, so that the sliding rod 1240 can move linearly along the Y-axis direction.

[0181] Additionally, a mounting bracket 1230 connecting the speed reduction unit 1220 and the rotating shaft housing 1140 can be provided at the end of the speed reduction unit 1220. Here, a central opening is formed inside the mounting bracket 1230, and the rotating shaft 1130 extends through the central opening. Here, the inner surface of the mounting bracket 1230 does not abut against or contact the rotating shaft 1130, and the mounting bracket 1230 does not rotate regardless of how the rotating shaft 1130 rotates; the position of the mounting bracket 1230 is fixed.

[0182] Sliding pins 1250 are fixed to the mounting bracket 1230, and multiple sliding pins 1250 can extend along the Y-axis direction. One end of each sliding pin 1250 is connected to the transmission frame 1310 of the distance holding unit 1310 described below, and the transmission frame 1310 can slide along the Y-axis direction on the sliding pins 1250. That is, the sliding pins 1250 can move the transmission frame 1310 relative to the mounting bracket 1230 along the Y-axis direction, but restrict the transmission frame 1310 from rotating about the Y-axis direction as the rotation center axis relative to the mounting bracket 1230. Therefore, the distance holding unit 1300 as a whole can perform only sliding transmission or linear transmission along the Y-axis direction relative to the tension control unit 1200. Here, the number or position of the sliding pins 1250 can vary in various ways and is not limited to those shown in the figure.

[0183] Additionally, the sliding rod 1240 can be fixed to one side of the transfer frame 1310, for example, as shown in the figure, fixed to the upper side of the transfer frame 1310. Here, the sliding rod 1240 and the transfer frame 1310 are fixed to each other, so no relative rotation or sliding is possible. Therefore, when the sliding rod 1240 moves along the Y-axis, the transfer frame 1310 also moves the same length along the Y-axis.

[0184] Therefore, with the deceleration unit 120, the fixed frame 130 and the sliding pin 1250 fixed, the driving force generated by the tension control motor 1210 is converted into enough force to make the sliding rod 1240 slide along the Y-axis direction, so that the sliding rod 1240 and the transmission frame 1310 slide simultaneously along the Y-axis direction, i.e., move linearly.

[0185] The distance holding unit 1300 includes the aforementioned transmission frame 1310, connecting frame 1320, and distance holding frame 1330, and constantly maintains the distance between the rotation drive unit 1100 and the rotation unit 1500.

[0186] As described above, the transfer frame 1310 is connected to the sliding rod 1240 and receives the sliding transfer force of the sliding rod 1240 along the Y-axis direction. Therefore, the transfer frame 1310 moves linearly on the sliding pin 1250, which acts as a transfer guide.

[0187] The connecting frame 1320 is spaced apart from the transfer frame 1310 by a predetermined distance along the Y-axis. Here, the distance holding frame 1330 maintains the distance between the connecting frame 1320 and the transfer frame 1310, and the distance between the connecting frame 1320 and the transfer frame 1310 can vary according to the extension length of the distance holding frame 1330 along the Y-axis.

[0188] The connecting frame 1320, the distance maintaining frame 1330, and the transmission frame 1310 are integrally formed together. Therefore, when the transmission frame 1310 moves linearly along the Y-axis, the connecting frame 1320 and the distance maintaining frame 1330 also move linearly along the Y-axis. In addition, a central opening is formed on the inner center of the transmission frame 1310, the connecting frame 1320, and the distance maintaining frame 1330, and the rotation axis 1130 extends through the central opening.

[0189] Here, the inner surfaces of the transmission frame 1310, the connecting frame 1320, and the distance holding frame 1330 do not contact the outer surface of the rotation shaft 1130. Therefore, the rotational force of the rotation shaft 1130 is not transmitted to the transmission frame 1310, the connecting frame 1320, and the distance holding frame 1330. In other words, the distance holding unit 1300 is not driven by the rotational force of the rotation shaft 1130.

[0190] See also the following text. Figure 20 The distance changes to unit 1400. Figure 20 It is shown Figure 16 A three-dimensional diagram of the distance changing unit and the connection status of the distance unit of the tension controller.

[0191] One side of the distance changing unit 1400 is connected to the distance holding unit 1300, and the other side of the distance changing unit 1400 is connected to at least one of the first hub unit 1600 and the second hub unit 1700, which will be described later. Therefore, the sliding transmission force in the Y-axis direction provided by the distance holding unit 1300 is transmitted to at least one of the first hub unit 1600 and the second hub unit 1700.

[0192] Specifically, the distance changing unit 1400 includes a distance changing frame 1410, a rotary bearing 1420, and an extension rod 1430.

[0193] The distance-changing frame 1410 has a doughnut shape, and a central opening 1411 is formed inside the distance-changing frame 1410. The distance-changing frame 1410 connects the connecting frame 1320 of the distance-holding unit 1300 to at least one of the first hub unit 1600 and the second hub unit 1700. That is, the distance-changing frame 1410 is connected to the connecting frame 1320, so the distance-changing frame 1410 can slide along the Y-axis direction. Additionally, the distance-changing frame 1410 is also connected to at least one of the first hub unit 1600 and the second hub unit 1700, so the distance-changing frame 1410 should rotate and be driven about the Y-axis as its rotation center axis. Therefore, as... Figure 20As shown, the rotary bearing 1420 is disposed between the connecting frame 1320 and the distance changing frame 1410, so that the distance changing frame 1410 can rotate and slide.

[0194] Specifically, one side of the rotary bearing 1420 can be fixed to the connecting frame 1320, and the other side of the rotary bearing 1420 can be disposed on the inner surface of the distance changing frame 1410. The rotary bearing 1420 can rotate on its own, and multiple rotary bearings can be provided. For example, as shown in the figure, three rotary bearings 1420 are provided at 120° intervals.

[0195] Furthermore, a central opening 1411 is formed at the center of the distance-changing frame 1410 and is open therein, and an inner groove 1415 is formed on the inner surface of the distance-changing frame 1410. Therefore, the outer surface of the other side of the rotary bearing 1420 is disposed in the inner groove 1415. Thus, the outer surface of each of the plurality of rotary bearings 1420 is disposed in the inner groove 1415, and the inner surface of the distance-changing frame 1410 contacts the outer surface of the rotary bearing 1420, causing the distance-changing frame 1410 to rotate relative to the rotary bearing 1420 about the Y-axis as its rotation center axis. Therefore, the distance-changing frame 1410 can rotate about the Y-axis as its rotation center axis while connected to the first hub unit 1600 and the second hub unit 1700.

[0196] Furthermore, the recess 1415 formed at the distance-changing frame 1410 is an inwardly recessed groove, and the other side of the rotary bearing 1420 is mounted on the recess 1415. That is, the outer surface of the rotary bearing 1420 is partially inserted into the recess 1415. Thus, when the rotary bearing 1420 is positioned at the recess 1415, the recess 1415 restricts the linear movement of the rotary bearing 1420 along the Y-axis direction. In other words, the rotary bearing 1420 cannot perform linear movement relative to the recess 1415 along the Y-axis direction. Therefore, the rotary bearing 1420, the connecting frame 1320 fixing one side of the rotary bearing 1420, and the distance-changing frame 1410 move together along the Y-axis direction. Finally, the distance-changing frame 1410 can slide along the Y-axis direction by connecting to the connecting frame 1320.

[0197] As described above, the distance changing frame 1410 and the distance changing unit 1400 including the distance changing frame 1410 can rotate about the Y-direction as the rotation center axis by the rotational force of the rotation drive unit 1100, and can move linearly along the Y-axis by the sliding force transmitted by the tension control unit 1200.

[0198] Additionally, the extension rod 1430 extends from the distance changing unit 1410 along the Y-axis direction to the first hub unit 1600 and the second hub unit 1700, which will refer to Figure 19 Detailed explanation. Figure 19 It is shown in magnification Figure 16 A three-dimensional view showing the connection status of the tension controller with the first and second wheel hub units.

[0199] One end of the extension rod 1430 is fixed to the distance changing unit 1410, so when the distance changing unit 1410 moves linearly along the Y-axis, the extension rod 1430 also moves linearly along the Y-axis. Multiple extension rods 1430, such as three extension rods 1430, can be arranged at 120° intervals, but the number of extension rods is not limited to this.

[0200] The extension rod 1430 extends through the second hub portion 1710 of the second hub unit 1700, which is adjacent to the distance changing unit 1410, and is ultimately fixed to the first hub portion 1610 of the first hub unit 1600. For this purpose, the first hub unit 1600 may further include a fixing portion 1630 configured to fix the other end of the extension rod 1430 to the interior of the first hub unit 1600. That is, the extension rod 1430 extending from the distance changing unit 1410 passes through the second hub portion 1710 and is then fixed to the first hub portion 1610. Here, the movement of the extension rod 1430 along the Y-axis is not restricted or interfered with by the second hub portion 1710, so the position of the second hub portion 1710 can be fixed regardless of the linear movement of the extension rod 1430. However, due to the linear movement of the distance changing unit 1410 along the Y-axis, the first hub portion 1610 moves linearly along the Y-axis as well.

[0201] By linearly moving the first hub portion 1610 along the Y-axis as described above, the distance between the first hub portion 1610 and the second hub portion 1710 can be relatively reduced or increased.

[0202] In addition, further reference will be made. Figure 18 The rotating unit 1500, the first hub unit 1600, and the second hub unit 1700 are described. Figure 18 It is shown in Figure 16 A 3D view showing the state after removing the second wheel hub unit.

[0203] The rotating unit 1500 includes a main rotating part 1510, a stepped frame 1520 and a central frame 1530.

[0204] The main rotating part 1510 may have a hollow cylindrical shape, and a central opening 1501 is formed at the center of the main rotating part 1510. A central frame 1530 can be inserted into and fixed to the central opening 1501. The central frame 1530 is connected to the end of the rotating shaft 1130, and the central frame 1530 receives the rotational force provided by the rotating shaft 1130, and therefore rotates about the Y-axis as the rotation center axis. Thus, since the central frame 1530 rotates about the Y-axis as the rotation center axis, the main rotating part 1510 also rotates about the Y-axis as the rotation center axis.

[0205] The first hub unit 1600 and the second hub unit 1700 are fixed to the outer surface of the main rotating part 1510, and as described above, the extension rod 1430 is connected. Here, the first hub unit 1600 and the second hub unit 1700 are fixed to the main rotating part 1510 and rotate together with the main rotating part 1510. At the same time, the first hub unit 1600 is slidably driven along the Y-axis direction on the outer surface of the main rotating part 1510.

[0206] Therefore, when the main rotating part 1510 rotates about the Y-axis, the first hub unit 1600 should maintain a constant adhesion force without slipping, and the first hub unit 1600 should be slidably in contact along the Y-axis. As described above, the sliding in the Y-axis direction is achieved by the sliding transmission force transmitted by the extension rod 1430, that is, by a predetermined force transmitted along the Y-axis. Finally, the first hub unit 1600 maintains the engagement state by maintaining a predetermined friction force on the outer surface of the main rotating part 1510, and thus, the first hub unit 1600 rotates with the rotation of the main rotating part 1510 by the aforementioned friction force. In addition, the sliding transmission force transmitted to the first hub unit 1600 through the extension rod 1430 should be greater than the friction force between the first hub unit 1600 and the main rotating part 1510, so the first hub unit 1600 can slide linearly along the Y-axis.

[0207] In contrast, the second hub unit 1700 remains fixed to the outer surface of the main rotating part 1510 and cannot slide. Specifically, the second hub unit 1700 is stably fixed to the main rotating part 1510 by a stepped frame 1520. That is, as Figure 18 As shown, the stepped frame 1520 protrudes from the outer surface of the main rotating part 1510 by a predetermined length at one end of the main rotating part 1510. Here, the protrusion height of the stepped frame 1520 should be less than the thickness of the second hub unit 1700. That is, the stepped frame 1520 is positioned to fix the lower part of the second hub part 1710 to the second hub unit 1700.

[0208] In addition, a plurality of fastening holes 1521 are formed at the stepped frame 1520. Although not shown in the figure, a plurality of fastening holes aligned with the fastening holes 1521 are also formed at the second hub portion 1710. Therefore, a separate connecting member, such as a pin, is provided between the fastening holes 1521 of the stepped frame 1520 and the fastening holes of the second hub portion 1710, thereby engaging and fixing the second hub unit 1700 to the stepped frame 1520.

[0209] Therefore, even though the second hub unit 1700 receives sliding force along the Y-axis direction through the extension rod 1430, the second hub unit 1700 is fixed to the step frame 1520 and does not slide.

[0210] Furthermore, since multiple extension rods 1430 extend outside the main rotating part 1510, the extension state of the extension rods 1430 may be interfered with by the stepped frame 1520 protruding from the main rotating part 1510. Therefore, in this exemplary embodiment, a groove 1522 is formed in the stepped frame 1520 at the position where the extension rod 1430 extends to prevent the extension rod 1430 from contacting the stepped frame 1520 during extension and to smoothly perform the sliding movement of the extension rod 1430 along the Y-axis direction.

[0211] The first hub unit 1600 includes a first hub portion 1610 and a first fixing portion 1620. The first hub portion 1610 is located on the main rotating portion 1510, and the inner surface of the first hub portion 1610 is in contact with the outer surface of the main rotating portion 1510. The first fixing portion 1620 is formed at constant intervals on the outer surface of one end of the first hub portion 1610.

[0212] Multiple first fixing portions 1620 may be formed at constant intervals along one side circumferential surface of the first hub portion 1610, and each of the first fixing portions 1620 may be a groove with a predetermined depth. The number of first fixing portions 1620 may be varied. Multiple wires serving as the support body 200 may be fixed at each of the first fixing portions 1620, as will be described in detail below.

[0213] Similarly, the second hub unit 1700 includes a second hub portion 1710 and a second fixing portion 1720. The second hub portion 1710 is disposed on the main rotating portion 1510, and the inner surface of the second hub portion 1710 contacts the outer surface of the main rotating portion 1510. The second fixing portion 1720 is formed at constant intervals on the outer surface of the other end of the second hub portion 1710.

[0214] Multiple second fixing portions 1720 may be formed at constant intervals along the other circumferential surface of the second hub portion 1710, and each of the second fixing portions 1720 may be a groove with a predetermined depth. The number of second fixing portions 1720 can be varied. Here, the other circumferential surface of the second hub portion 1710 where the second fixing portions 1720 are formed is the opposing circumferential surface facing the circumferential surface of the first hub portion 1610; therefore, the first fixing portion 1620 and the second fixing portion 1720 are formed at the opposite side ends of a pair of hub units 1600 and 1700, respectively. Multiple wires serving as the support 200 may also be fixed at each of the second fixing portions 1720.

[0215] In the following text, refer to Figure 21 This describes the state of multiple lines set in the first hub unit 1600 and the second hub unit 1700. Figure 21 This is a magnified perspective view showing the first and second hub units with multiple lines. Figure 21 For ease of explanation, the tension control section has been omitted.

[0216] Each line connects to one of the multiple unit blocks 100 and the first hub unit 1600 and the second hub unit 1700. That is, each line starts from one of the multiple unit blocks 100, extends through the first fixing part 1620 and the second fixing part 1720, and then extends to another unit block.

[0217] Specifically, the line extends radially from one unit block toward the first hub unit 1600 and the second hub unit 1700 and is fixed within the first fixing portion 1620 formed by the groove, then changes direction to the Y-axis direction. The line then extends along the Y-axis direction, passing through the inner surfaces of the first hub portion 1610 and the second hub portion 1710, then changes direction again toward the radial direction of a unit block and is fixed to the second fixing portion 1720 formed by the groove, extending to the unit block. Here, the line is fixed to the first fixing portions 1620 and the second fixing portions 1720 arranged in a row along the Y-axis direction. Here, a single line forms a closed loop along a unit block and the first fixing portions 1620 and the second fixing portions 1720, and extends as a whole without being discontinuous.

[0218] Figure 22 It is shown Figure 16 A perspective view of the first and second hub units separated by the tension control unit, and 23 is shown. Figure 16 A perspective view of the approach state of the first and second hub units through the tension control unit.

[0219] As described above, since the multiple lines extend in a fixed state between the first hub unit 1600 and the second hub unit 1700, the tension applied to the multiple lines may change due to the change in the distance between the first hub unit 1600 and the second hub unit 1700.

[0220] like Figure 22 As shown, as the distance between the first hub unit 1600 and the second hub unit 1700 increases, the tension applied to the multiple lines connected in a closed loop between the unit block 100 and the first hub unit 1600 and the second hub unit 1700 also increases.

[0221] In contrast, such as Figure 23 As shown, as the distance between the first hub unit 1600 and the second hub unit 1700 decreases, the tension applied to the multiple lines decreases. That is, when the first hub unit 1600 and the second hub unit 1700 approach each other to make contact, the tension applied to the multiple lines is minimized.

[0222] As described above, the tension applied to the support 200 corresponding to the spokes of the wheel unit 10 can be adjusted by adjusting the distance between the first hub unit 1600 and the second hub unit 1700. Therefore, appropriate tension can be applied for various driving conditions.

[0223] For example, on a relatively flat surface without curves, by increasing the tension of the support 200 to drive the wheel unit 10, the wheel unit 10 can maintain its circular shape and travel on the ground at a relatively high speed. Furthermore, by controlling the contact angle with the ground based on ground tension, the height of the wheel unit 10 can be easily adjusted (see reference). Figure 3 ).

[0224] In contrast, for surfaces with significant curvature, the wheel unit 10 is driven by reducing the tension of the support 200. This allows the wheel unit 10 to effectively absorb the impact caused by the curvature of the ground and maintain stability and directionality regardless of the curvature. Furthermore, when traversing obstacles such as stairs, similar to the approach for surfaces with significant curvature, the wheel unit 10 travels with reduced tension on the support 200. This allows for more effective absorption of the impact generated when overturning obstacles and enables stable overturning of obstacles.

[0225] like Figure 16 As shown, the wheel unit 10 according to this example embodiment may further include a controller 1800 configured to control the tension applied by the support 200.

[0226] When wheel unit 10 traverses a relatively flat surface without curvature, controller 1800 can relatively increase the tension of support 200. Here, on a relatively flat surface without curvature, the reaction force applied to wheel unit 10 is constant, so stable passage is possible even when the relative deformation of wheel unit 10 is minimized.

[0227] In contrast, when wheel unit 10 traverses a relatively curved surface or encounters an obstacle in front of wheel unit 10, controller 1800 can relatively reduce the tension on support body 200. That is, the tension applied by support body 200 can be reduced by decreasing the distance between the first hub unit 1600 and the second hub unit 1700. This is because the reaction force applied to wheel unit 100 from the ground is irregular, thus it is more advantageous for wheel unit 10 to slightly deform and effectively absorb impact while traversing the terrain.

[0228] For this purpose, the controller 1800 is connected to the tension control unit to adjust the distance between the first hub unit 1600 and the second hub unit 1700. Furthermore, the controller 1800 can also control the tension of the elastic line 400.

[0229] Therefore, while maintaining a driving speed based on rotation to cope with various driving environments, the tension of the wheel unit's support body can be controlled by adjusting the distance of the wheel hub unit, thereby eliminating the need for structural deformation of the wheel unit used to control tension and achieving simple and fast tension control.

[0230] In particular, the components of the tension control unit are optimized to perform sliding movement while maintaining the transmission of the aforementioned rotational force, thus enabling relatively easy manufacturing and operation.

[0231] Thanks to the tension control of the support structure, the wheel unit can be optimally adjusted to adapt to various driving environments, including constantly curved surfaces or surfaces with significant curvature. Furthermore, when traversing obstacles, the tension can be optimally controlled to meet the traversal requirements.

[0232] Then, refer to Figure 24 and Figure 25 The wheel unit 10' for overcoming obstacles according to the second embodiment of the present invention is described. Figure 24 A front view showing the state of a wheel unit for traversing obstacles according to a second embodiment of the present invention passing over the ground. Figure 25 It is shown Figure 24 The main view of the wheel unit as it flips over an obstacle.

[0233] Reference Figure 24 and Figure 25The wheel unit 10′ according to this example embodiment includes a plurality of unit blocks 2100, a support body 2200, a hub portion 2300, and an elastic line 2400. The wheel unit 10′ according to the second embodiment differs from the wheel unit 10 according to the previous first embodiment only in the shape and connection structure of the unit blocks, while the support body, hub portion, and elastic line are the same. Therefore, the shape and connection structure of the unit blocks will be described in detail.

[0234] Multiple unit blocks 2100 are spaced apart from the hub portion 2300 by a predetermined distance and arranged in a circumferential direction. Each unit block 2100 is adhered to each other and connected to form a circular shape, and together they form the outer shape of the wheel unit 10'. Among the multiple unit blocks 2100, adjacent unit blocks 2100 can rotate and move relative to each other, so adjacent unit blocks 2100 can adhere to each other, or the adhesion between adjacent unit blocks can be released.

[0235] Reference Figure 24 When wheel unit 10′ passes over flat ground 1, multiple unit blocks 2100 are bonded together by adhering to each other through the structure described below, and support body 2200 simultaneously applies tension to multiple unit blocks 2100 toward hub portion 2300. Further, as mentioned above, elastic line 2400 can also apply tension in the direction of hub portion 2300 to multiple unit blocks 2100.

[0236] Reference Figure 25 When one side of wheel unit 10′ collides with an obstacle 6, such as a step, located on the ground 1, wheel unit 10′ begins to deform at the collision location. That is, at the contact portion A, the shape of wheel unit 10′ collapses and reflects the shape of obstacle 6, and the engagement state of wheel unit 10′ changes due to the relative rotation and movement between adjacent unit blocks 2100. Here, because the hub portion 2300 rotates continuously, even if the shape of the unit block 2100 collapses, the hub portion 2300 will rotate around the contact portion A, while wheel unit 10′ tumbles over obstacle 6.

[0237] Reference Figure 26 and Figure 27 This describes the detailed structure of each unit block 2100 and the connection status between adjacent unit blocks 2100. Figure 26 It is shown Figure 24 A three-dimensional diagram of the unit block of the wheel element, and Figure 27 It is shown Figure 26 A 3D diagram showing the state of a pair of unit blocks combined together.

[0238] Each of the unit blocks 2100 includes a main body 2110, a connecting part 2120, a groove part 2130, and a fixing part 2140.

[0239] The main body 2110 forms the main body of the unit block 2100, and as shown in the figure, it has a cylindrical shape overall. The connecting part 2120 extends from one side of the main body 2110. The main body 2110 has a predetermined width, and the width of the main body 2110 can be varied.

[0240] Specifically, the main body 2110 includes a rotating body 2111 having a curved surface with an arc-shaped outer surface, a first side surface 2112 and a second side surface 2113 forming two side surfaces of the rotating body 2111, and an extended surface 2114 extending from one side of the rotating body 2111 and connected to the connecting portion 2120 described later.

[0241] The rotating body 2111 is cylindrical in shape, and a connecting portion 2120 is connected to one side of the rotating body 2111. In particular, the upper side of the rotating body 2111 extends upward to an extended surface 2114 having an outer surface forming a curved surface. Here, for ease of explanation, refer to... Figure 26 It can be interpreted as "upper side," but it can essentially be "lower side," and the "lower side" explained later can also be "upper side." Here, the outer surface of the rotating body 2111 has a cylindrical outer surface shape with a protruding shape, but conversely, the extended surface 2114 extends with a concave curved surface.

[0242] A pair of fixing portions 2140 protrude from each of the first side surface 2112 and the second side surface 2113. That is, the upper fixing portion 2141 and the lower fixing portion 2142 protrude from the first side surface 2111. The upper fixing portion 2141 and the lower fixing portion 2142 are spaced apart from each other, and a predetermined fixing space 2143 is formed between them. Similarly, although not shown in the figure, the upper fixing portion and the lower fixing portion protrude from the second side surface 2113, and a predetermined fixing space is formed therebetween.

[0243] The elastic line 2400 extends and is fixed through the fixed space 2143, and the spacing of the fixed space 2143 can be varied, taking into account factors such as the thickness of the elastic line 2400. That is, the elastic line 2400 is fixed along the fixed space 2143 and extends throughout the multiple unit blocks 2100, so that the elastic force of the elastic line 2400 can be provided toward the hub portion 2300 to the multiple unit blocks 2100, and adhesive force can be provided between the multiple elastic blocks 2100.

[0244] The connecting portion 2120 extends from one side of the main body 2110 and forms an insertion space into which the main body of an adjacent unit block is inserted to adhere to the main body of the adjacent unit block. Specifically, the connecting portion 2120 includes a first connecting surface 2121, a second connecting surface 2122, a contact surface 2123, a first side surface 2125, and a second side surface 2126.

[0245] The first connecting surface 2121 extends from the extended surface 2114. The outer surface of the first connecting surface 2121 forms a flat, extending plane, and the outer surface of the first connecting surface 2121 becomes sharper and more protruding as it moves away from the body 2110. The second connecting surface 2122 extends from the opposite side of the extended surface 2114. The outer surface of the second connecting surface 2122 also forms a flat, extending plane, and the outer surface of the second connecting surface 2122 becomes sharper and more protruding as it moves away from the body 2110. Here, the groove portion 2130, described later, is formed on the underside of the rotating body 2111, and the second connecting surface 2122 extends from the rotating body 2111 such that the second connecting surface 2122 has a shape that extends flatly after a predetermined groove is formed on the underside of the rotating body 2111. The second connecting surface 2122 has a flat outer surface as it extends from the first connecting surface 2121, but the outer surfaces of the first connecting surface 2121 and the second connecting surface 2122 do not need to be designed to be parallel to each other.

[0246] As the first connecting surface 2121 and the second connecting surface 2122 extend to become sharper towards their ends, the contact surface 2123 connecting the first connecting surface 2121 and the second connecting surface 2122 is formed with a concave curved surface shape. That is, the contact surface 2123 extends from the end of the first connecting surface 2121 to the end of the second connecting surface 2122, and has a concave curved surface shape corresponding to the outer surface of the cylinder. Here, the curvature of the concave shape of the contact surface 2123 is substantially the same as the curvature of the convex shape of the rotating body 2111. Therefore, as Figure 27 As shown, the outer surface of the rotating body 2111 of the second unit block 2100b can adhere to the contact surface 2123 of the first unit block 2100a adjacent to the second unit block 2100b.

[0247] In other words, the first connecting surface 2121, the second connecting surface 2122, and the contact surface 2123 form an insertion space 2124 within them, and the main body 2110 of the adjacent unit block is inserted into and adhered to the insertion space 2124. Therefore, the multiple unit blocks 2100 are held together in a state of mutual adhesion.

[0248] The first side surface 2125 and the second side surface 2126 of the connecting portion 2120 extend from the first side surface 2112 and the second side surface 2113 of the main body 2110, respectively. Therefore, the first side surface 2125 and the second side surface 2126 form the two side surfaces of the unit block 2100.

[0249] A groove 2130 extends from the lower side of the rotating body 2111 and is formed between the rotating body 2111 and the second connecting surface 2122 of the connecting portion 2120. Specifically, the groove 2130 includes an extending curved surface 2131 and an extending vertical surface 2132. The extending curved surface 2131 extends from the lower side of the rotating body 2111 with the same curvature as the rotating body 2111. The extending vertical surface 2132 extends downward from the end of the extending curved surface 2131, forming a flat surface. Here, when the groove 2130 is formed on the upper side of the rotating body 2111, the extending vertical surface 2132 can extend upward from the extending curved surface 2131. Therefore, since the extending curved surface 2131 and the extending vertical surface 2132 extend with different curvatures, a supporting groove 2133 is formed between the extending curved surface 2131 and the extending vertical surface 2132, and the concave shape of the supporting groove 2133 can be pointed.

[0250] In the following text, refer to Figure 28 and Figure 29 This illustrates the relative connection relationships when unit block 2100 overcomes obstacles. Figure 28 It is shown Figure 25 A front view of the changing state of the unit block at contact part A when the wheel unit traverses an obstacle. Figure 29 It is shown Figure 25 The front view of the changing state of the unit block at adjacent part B when the wheel unit crosses an obstacle.

[0251] Reference Figure 28 When the wheel unit 10′ according to this embodiment traverses the obstacle 6, at the contact portion A, the engagement state of adjacent unit blocks 2100 changes, causing the adjacent unit blocks 2100 to bend radially outward and engage. Normally, in order to traverse the obstacle 6, the unit block 2100 is fixed at the contact point that contacts the obstacle 6, and the unit block 100 rotates around the contact point. To perform the above rotation, the inner side of the unit block 2100 should be able to deform relatively freely. Thus, while the unit block 2100 rotates around the contact point, the obstacle 6 can be easily traversed.

[0252] In this regard, refer to Figure 28 Explain the combination relationship between adjacent unit blocks 2100 at contact A. For example... Figure 27 As shown, when the adjacent first unit block 2100a and second unit block 2100b are in contact with the obstacle 6 while they are in a state of mutual adhesion, the adjacent first unit block 2100a and second unit block 2100b rotate relative to each other in a direction of radial outward bending.

[0253] Therefore, the second connecting surface 2122 of the first unit block 2100a moves along the outer surface of the rotating body 2111 of the second unit block 2100b and is positioned and inserted into the support groove 2133 of the second unit block 2100b. Here, the curvature of the extended surface 2131 is the same as the curvature of the rotating body 2111 and the curvature of the contact surface 2123, so the end of the second connecting surface 2122 of the first unit block 2100a can be smoothly inserted into the support groove 2133 of the second unit block 2100b.

[0254] Here, the extended vertical surface 2132 of the groove 2130 has a flat surface. Therefore, when the end of the second connecting surface 2122 of the first unit block 2100a is inserted into the inner side of the support groove 2133 of the second unit block 2100b, further movement can be restricted due to the extended vertical surface 2132. Thus, the degree of relative rotation between adjacent unit blocks 2100 can be limited.

[0255] Ultimately, the outer surface of the second connecting surface 2122 of the first unit block 2100a, which is a flat surface, contacts the vertical surface of the obstacle 6, and the outer surface of the second connecting surface 2122 of the second unit block 2100b, which is also a flat surface, contacts the flat surface of the obstacle 6. Here, it is not necessary for both adjacent second connecting surfaces 2122 to maintain contact with both vertical surfaces of the obstacle 6, and the contact state can be variably changed, for example, sequential contact, taking into account the state of the two vertical surfaces of the obstacle 6. However, the support groove 2133 and the end of the second connecting surface 2122 inserted into the support groove 2133 substantially coincide with the contact point 7 of the obstacle 6, and the wheel unit 10′ as a whole provides rotational force in a clockwise direction, so the adjacent first unit blocks 2100a and second unit blocks 2100b rotate around the contact point 7 and tumble over the obstacle 6.

[0256] Furthermore, in order to traverse the obstacle 6 with the contact point 7 as the center, the inner side of the unit block 2100 in contact with the obstacle 6 should be able to deform freely. Therefore, in this example embodiment, the rotating body 2111 of the second unit block 2100b is inserted into the insertion space 2124 of the first unit block 2100a, and can rotate freely relative to each other while in close contact. Thus, the inner side of the unit block 2100 can deform freely.

[0257] In particular, when the first unit block 2100a and the second unit block 2100b, which are adjacent to each other, rotate in close contact, the distance between the center C of the body 2110 of the first unit block 2100a and the center C′ of the body 2110 of the second unit block 2100b remains constant and does not change. Therefore, the unit block 2100 in contact with the obstacle 6 can maintain a relatively stable posture and can stably absorb the external force generated when in contact with the obstacle 6 to overcome the obstacle.

[0258] Here, the adhesive force between the unit blocks is maintained by the elastic line 2400 that passes through the fixed space 2143 and connects the unit blocks 2100, so that the obstacle can be crossed stably.

[0259] Therefore, when the interconnected unit blocks come into contact with an obstacle, the inner side rotates freely, while the outer side is fixed so that it can rotate around the contact point 7. Thus, there is no problem such as the wheel unit 10' popping out upon contact with an obstacle, and the external force generated upon contact with the obstacle is fully absorbed, allowing for effective obstacle clearance.

[0260] Furthermore, when the wheel unit 10′ is overcoming the obstacle 6, unlike the close contact and relative rotation of the unit block 2100 in the contact part A, the relative position of the unit block 2100 changes in a different way in the adjacent part B.

[0261] Reference Figure 29 Regarding the third unit block 2100c and the fourth unit block 2100d that are adjacent to each other in adjacent part B, the outer parts are deformed to move away from each other due to tension, but the inner parts are deformed to move closer to each other due to compressive force. Therefore, the state in which the adjacent third unit block 2100c and the fourth unit block 2100d are in close contact with each other is released and they are in a split state with the inner side as the center.

[0262] That is, the fourth unit block 2100d, which is adjacent to the third unit block 2100c, rotates as a whole in a radially inward direction, i.e., toward the hub portion 2300, so that the main body 2110 of the fourth unit block 2100d disengages from the insertion space 2124 of the third unit block 2100c. Here, the first connecting surface 2121 of the third unit block 2100c moves along the extended surface 2114 of the fourth unit block 2100d.

[0263] Finally, the distance between the center C of the body 2110 of the third unit block 2100c and the center C′ of the body 2110 of the fourth unit block 2100d increases with the aforementioned separation. However, at this time, due to the concave curvature of the extended surface 2114, the movement of the first connecting surface 2121 of the third unit block 2100c along the extended surface 2114 of the fourth unit block 2100d is restricted to a distance beyond a predetermined distance. Therefore, the adjacent third unit block 2100c and fourth unit block 2100d remain in a separated state until... Figure 29 The degree indicated.

[0264] That is, even if adjacent unit blocks 2100 are divided, it is possible to prevent them from being completely separated into a state of mutual contact. In this example embodiment, since the elastic line 2400 maintains the adhesion between adjacent unit blocks 2100, it is possible to prevent the unit blocks 2100 from being completely separated and the overall shape of the wheel unit 10' from collapsing.

[0265] Thus, the tensile force applied to the outside of the unit block 2100 in the adjacent part B is absorbed by the elastic line 2400, and the compressive force applied to the inside of the unit block 2100 is absorbed by the extended surface 2114 and the first connecting surface 2121 fixed to the extended surface 2114. Therefore, the unit blocks 2100 adjacent to each other will not shift or their relative positions will not change irregularly, and the overall shape of the wheel unit 10′ can remain constant.

[0266] For reference Figure 28 and Figure 29 As explained, when the wheel unit 10′ crosses the obstacle 6, in each of the contact part A and the adjacent part B, the adjacent unit blocks maintain different bonding relationships and change their relative positions, but the overall shape of the wheel unit 10′ can be maintained and the obstacle can be crossed stably.

[0267] In particular, due to the specific structure of the unit block 2100 according to this example embodiment, during the process of traversing the obstacle 6, regardless of whether the unit block 100 is located at the contact portion A or the adjacent portion B, it can be in close contact with or freely separated from the adjacent unit block, and the change in relative position can be further restricted. Therefore, the wheel unit 10′ can effectively traverse obstacles.

[0268] According to the example embodiment described above, based on the principle that water droplets maintain their appearance through surface tension, a force similar to the surface tension of water droplets is simulated by the tension applied by the support and the adhesive force between the unit blocks applied by the elastic line, so that the wheel unit maintains its overall shape and passes through the ground effectively.

[0269] In addition, by applying the principle that the shape collapses when a force exceeding the critical deformation angle is applied to a water droplet, when the wheel unit comes into contact with an obstacle, the unit blocks at the contact part adhere to each other and the spacing is fixed, while the adjacent unit blocks adjacent to the contact part are released from the adhesion state and the spacing is increased, thereby effectively overcoming obstacles.

[0270] Here, through the structure of the unit blocks, the tension after passing over obstacles, and the elasticity of the elastic lines, the collapsed parts of the wheel unit can be easily restored to their original shape, thus maintaining the original shape of the wheel unit. Therefore, the wheel unit can smoothly traverse obstacles and travel on the ground.

[0271] In particular, each of the unit blocks includes a body with an arc-shaped protruding outer surface and a connecting portion with an arc-shaped concave shape. Therefore, the body inserts into the connecting portion of adjacent unit blocks and can rotate relative to them, thereby maintaining stable and efficient movement when traversing obstacles or traveling on flat ground.

[0272] That is, when traversing obstacles, in the contact section, between adjacent unit blocks, the main body and connecting part rotate relative to each other and come into close contact. In particular, the degree of relative rotation is limited by the groove, thus achieving a stable support structure. In contrast, in the adjacent section, between adjacent unit blocks, the main body and connecting part are separated from each other, and their relative positions can be freely changed within a predetermined range. Therefore, the applied force is distributed, and the overall structure of the wheel unit can be maintained.

[0273] Here, the elastic lines fix adjacent unit blocks together with a predetermined elastic force, so that even if the force is concentrated in a specific unit block, the force can be distributed as a whole, and the degree of division between the segmented unit blocks can be limited within a certain range. Therefore, the wheel structure can effectively overcome obstacles and maintain stability.

[0274] As described above, the wheel unit 10′ according to the second embodiment may further include a tension control unit configured to control the tension applied by the support body. That is, the wheel unit 10′ may further include a rotation drive unit, a tension control unit, a distance holding unit, a distance changing unit, a rotation unit, and a controller, all serving as the tension control unit. The hub portion 2300 may be composed of a first hub unit and a second hub unit spaced apart from each other along the axial direction. Therefore, the tension applied by the support body 2200 is adjusted by regulating the distance between the first hub unit and the second hub unit.

[0275] Then, refer to Figure 30 and Figure 31 The wheel unit 10″ for overcoming obstacles according to the third embodiment of the present invention is described. Figure 30This is a front view showing the state of a wheel unit for traversing obstacles passing over the ground according to a third embodiment of the present invention. Figure 31 It is shown Figure 30 The main view of the wheel unit as it flips over an obstacle.

[0276] Reference Figure 30 and Figure 31 The wheel unit 10″ according to this embodiment includes a plurality of unit blocks 3100, a support body 3200, and a hub portion 3300. Compared with the wheel unit 10 according to the first embodiment described above, the wheel unit 10″ according to the third embodiment is different only in the shape and connection structure of the unit blocks, while the structure of the support body and the hub portion is the same. Therefore, the shape and connection structure of the unit blocks will be described in detail.

[0277] Multiple unit blocks 3100 are spaced apart from the hub portion 3300 by a predetermined distance and arranged in a circumferential direction. Each unit block 3100 is adhered to each other to form a circular shape as a whole, forming the outer shape of the wheel unit 10″. Among the multiple unit blocks 3100, adjacent unit blocks 3100 rotate and move relative to each other. Therefore, adjacent unit blocks 3100 can adhere to each other, or the adhesion between adjacent unit blocks can be released.

[0278] Reference Figure 30 When wheel unit 10″ passes over flat ground 1, multiple unit blocks 3100 are bonded together by adhering to each other through the structure described below, while support body 3200 applies tension to multiple unit blocks 3100 in the direction toward hub portion 3300. Further, although not shown in the figure, elastic lines can be arranged around multiple unit blocks 3100, thereby applying tension to multiple unit blocks 3100 in the direction toward hub portion 3300 and providing adhesive force between multiple unit blocks 3100.

[0279] Reference Figure 31 When one side of wheel unit 10″ collides with an obstacle 6, such as a step on the ground 1, wheel unit 10″ begins to deform at the collision location. That is, at the contact portion A, the shape of wheel unit 10″ collapses and reflects the shape of obstacle 6, and the engagement state of wheel unit 10′ changes due to the relative rotation and movement between adjacent unit blocks. Here, since the hub portion 3300 rotates continuously, even if the contact portion A collapses, the hub portion 3300 rotates around the contact portion A, while the wheel unit 10 tumbles over the obstacle 6.

[0280] Furthermore, unlike the first and second embodiments, in the third embodiment, the adhesion state of the unit blocks 3100 adjacent to each other in the contact portion A and the adjacent portion B is released. However, even though the unit blocks 3100 are released from the adhesion state at the contact portion A, the outer surfaces of the unit blocks 3100 adhere to each other and a predetermined adhesive force is applied, so the adhesion state of the unit blocks 3100 can be restored again.

[0281] Figure 32 This is a schematic diagram illustrating the force transmission state when a traditional wheel unit overturns an obstacle, and Figure 33 It is shown Figure 30 A schematic diagram of the force transmission state of the wheel unit when it traverses an obstacle. Before explaining the specific structural deformation of the wheel unit 10″ when it traverses obstacles such as stairs according to this embodiment, the force transmission state of the wheel unit 10″ when it traverses stairs will be explained first.

[0282] Here, to illustrate the advantages of the wheel unit 10″ of this embodiment, it is assumed that the conventional wheel unit 11 has a structure in which the unit blocks 101 forming the shape are fixed in close contact with each other and are not detachable from each other. That is, as Figure 32 As shown, in the conventional wheel unit 11, the outer and inner surfaces of the unit block 101 do not form a segmented structure, but rather a continuously extending curved structure.

[0283] When the conventional wheel unit 11 contacts and traverses the steps, an external force is applied from the steps to the outer surface of the unit block 101. This generates compression in the contact portion of the outer surface, and consequently, tension in the inner surface facing the outer surface. However, in the case of the conventional unit block 101, since the outer and inner surfaces are continuously extended curved structures with their interlocking state intact, the compression and tension forces remain at similar levels, thus forming a neutral surface along the center of the unit block 101. Furthermore, since the inner surface of the unit block 101 is not segmented and extends continuously, depending on the material of the inner surface, only tensile strain can be achieved within a certain range, and tensile strain exceeding this range cannot be achieved in the unit block 101.

[0284] Therefore, in Figure 32 In a conventional wheel unit 11, when traversing an obstacle such as a staircase, if the tensile strain exceeds a certain range, the wheel unit 11 may be unable to traverse the staircase, for example, by colliding with the staircase and bouncing up.

[0285] On the contrary, such as Figure 33The wheel unit 10″ shown in this embodiment includes a segmentation structure in which the unit blocks 3100 are detachable from each other and the inner surfaces of the unit blocks 3100 are separable from each other. When an external force is applied from the steps, the tensile strain is not limited due to the segmentation of the inner surfaces of the unit blocks 3100, so the tensile strain can be increased indefinitely (possibly to the maximum tensile strain).

[0286] Therefore, the tensile strain applied to the inner surface is not limited to a certain range. The neutral surface of the unit block 3100 is formed close to the outer surface, and the tensile strain on the inner surface is realized to be relatively much larger, so that the wheel unit 10″ can easily climb over the steps.

[0287] That is, when wheel unit 10″ contacts the step, the inner surface of the unit block can freely deform around the outer surface of the unit block 3100 in contact with the step. Therefore, due to the rotational driving force of wheel unit 10″, wheel unit 10″ rotates around the outer surface of the unit block 3100 in contact with the step, and wheel unit 10″ deforms to conform to the shape of the step, thus easily overcoming the step. Therefore, when wheel unit 10″ contacts an obstacle such as a step, unit block 3100 can be freely deformed by segmentation, and there is no limitation on tensile strain. Therefore, obstacles can be easily overcoming.

[0288] Figure 34 and Figure 35 It is shown Figure 31 The front view shows the deformation of the element block at contact point A when the wheel element traverses an obstacle. Before explaining the deformation state of the element block at contact point A, first refer to... Figure 34 and Figure 35 This describes the detailed structure of unit block 3100 and the connection and division states between adjacent unit blocks 3100.

[0289] Each of the multiple unit blocks 3100 includes a main body 3110, a recess 3120, a protrusion 3130, a fixing part 3140, and a support part 3150.

[0290] The main body 3110 forms the main body of the unit block 3100, and the main body 3110 can move along... Figure 34 The vertical direction has a predetermined width. Here, the width of the main body 3110 can be changed in various ways.

[0291] The main body 3110 includes an upper surface 3111 forming an upper side surface and a lower surface 3112 forming a lower side surface. Here, the lower surface 3112 extends as a flat surface, but the upper surface 3111 extends in the same direction as the lower surface 3112, and then the front end of the upper surface 3111 extends as a downwardly curved surface.

[0292] The main body 3110 may further include a front surface portion 3115 extending from the upper surface and forming the front of the main body 3110, and a rear surface portion 3116 disposed on the rear side of the front surface portion 3115 and forming the rear of the main body 3110. The front surface portion 3115 extends and protrudes from the upper surface 3111, and unlike the front surface portion 3115, the rear surface portion 3116 is recessed. Here, as... Figure 34 As shown, in adjacent unit blocks, the front surface portion 3115 of the first unit block 3100a can adhere to the rear surface portion 3116 of the second unit block 3100b and then be inserted into the rear surface portion 3116 of the second unit block 3100b. That is, the front surface portion 3115 of the first unit block 3100a is located at the rear surface recess 3117 formed by the rear surface portion 3116 of the second unit block 3100b, and then adheres to the rear surface portion 3116. Here, the protruding shape of the front surface portion 3115 should be designed as an extended surface with the same curvature as the rear surface portion 3116, so that the front surface portion 3115 can adhere to and be inserted into the recessed portion of the rear surface portion 3116.

[0293] Furthermore, the main body 3110 further includes a front surface recess 3113 extending from the front end of the lower surface 3112 and a rear surface protrusion 3118 extending from the rear end of the lower surface 3112. The front surface recess 3113 is recessed and extends in a concave and surrounding shape on the extension surface extending from the front end of the rear surface 3112 to the front surface portion 3115. Here, the entire length from the front end of the lower surface 3112 to the front surface portion 3115 forms a protruding curved surface, but the front surface recess 3113 is recessed and extends. In addition, the rear surface protrusion 3118 protrudes and extends in a convex and surrounding shape on the extension surface extending from the rear end of the lower surface 3112 to the rear surface portion 3116. That is, the entire length from the rear end of the lower surface 3112 to the rear surface portion 3116 forms a concave curved surface, but the rear surface protrusion 3118 protrudes and extends. Here, the recessed shape of the front surface recess 3113 has the same curvature as the protruding shape of the rear surface protrusion 3118 of the adjacent unit block so that they can adhere to each other. That is, as Figure 34 As shown, when adjacent unit blocks adhere to each other, the rear surface protrusion 3118 of the second unit block 3100 adheres to the front surface recess 3113 of the first unit block 3100a.

[0294] Furthermore, a recessed portion 3120 is formed with a predetermined length between the front surface portion 3115 and the front surface recessed portion 3113. For example... Figure 34 As shown, the groove portion 3120 is formed along... Figure 34The groove has a predetermined distance in the vertical direction, so the groove portion 3120 and the side surface forming the front surface portion 3115 form a stepped portion. In addition, the protrusion 3130 protrudes from the rear surface 3114 by a predetermined length and is formed at the groove portion 3120 of the adjacent unit block.

[0295] like Figure 34 As shown, when adjacent unit blocks are adhered to each other, the protrusion 3130 of the second unit block 3100b is located on the groove 3120 of the first unit block 3100a. Specifically, when the first unit block 3100a and the second unit block 3100b are adhered to each other, the protrusion 3130 of the second unit block 3100b is located at the lower end of the groove 3120 of the first unit block 3100a. Furthermore, when the relative position between adjacent unit blocks changes, the position of the protrusion 3130 can change within the groove 3120, which has a predetermined length. That is, the protrusion 3130 can slide within the groove 3120.

[0296] As described above, when the protrusion 3130 is formed on the groove 3120, the adhesive force between the unit blocks can be increased. In addition, even if the relative position of the unit blocks changes, the protrusion 3130 can remain within the groove 3120 within a predetermined range. Therefore, the adhesiveness between the unit blocks can be maintained, and the relative positional movement between the unit blocks can be restricted.

[0297] The fixing portion 3140 extends from the upper side of the main body 3110 and includes a fixing protrusion 3141, a contact surface 3142, and an end portion 3143. The fixing protrusion 3141 extends from the rear side of the upper surface 3111 and the rear surface portion 3116 of the main body 3110. The fixing protrusion 3141 extends toward the upper rear end of the main body 3110 to form a predetermined step portion 3119 with the upper surface 3111. The contact surface 3142 forms the lower surface of the fixing portion 3140, and the contact surface 3142 is a surface that extends continuously from the rear surface 3116. In addition, the end portion 3143 is formed at the rearmost end of the contact surface 3142 and protrudes to form the rear end of the fixing portion 3140.

[0298] like Figure 34 As shown, when adjacent unit blocks adhere to each other, the contact surface 3142 of the fixing part 3140 of the second unit block 3100b adheres to the upper surface 3111 of the first unit block 3100a. For this purpose, the curvature of the curved surface of the contact surface 3142 can be the same as the curvature of the upper surface 3111.

[0299] Furthermore, the end 3143 of the second unit block 3100b may be located at the step portion 3119 at the connection between the upper surface 3111 of the first unit block 3100a and the fixing portion 3140. Therefore, the end 3143 is located at the step portion 3119, thereby limiting the relative positional changes between adjacent unit blocks, which will be explained below.

[0300] The support portion 3150 is coupled to the lower surface 3112 and includes a support frame 3151 and a first support protrusion 3152 or a second support protrusion 3153. Here, for a plurality of unit blocks 3100, the first support protrusion 3152 and the second support protrusion 3153 may be formed alternately. That is, if the second unit block 3100b includes the first support protrusion 3152, then the first unit block 3100a includes the second support protrusion 3153.

[0301] Specifically, the support frame 3151 is fixed to the lower surface 3112, and since the lower surface 3112 extends with a flat surface, the support frame 3151 also extends parallel to the flat surface. A first support protrusion 3152 or a second support protrusion 3153 protrudes a predetermined length vertically from the lower surface of the support frame 3151. Therefore, when viewed from the side, the support frame 3151 and the first support protrusion 3152 or the support frame 3151 and the second support protrusion 3153 can generally have... Shaped as such. Thus, because the support part 3150 is shaped as seen from the side. The shape allows for more effective support or fixation with obstacles such as vertically shaped steps, making it easier to climb over them.

[0302] Refer to the following Figure 37 For example, when the support portion 3150 of the fourth unit block 3100d includes a second support protrusion 3153 and the support portion 3150 of the third unit block 3100c includes a first support protrusion 3152, the second support protrusion 3153 has a pair of protrusions spaced apart from each other to form an insertion space 3154 at the center between the pair of protrusions, and the first support protrusion 3152 includes a protrusion located at the center where the insertion space 3154 is formed.

[0303] Therefore, as Figure 35As shown, when adjacent unit blocks overlap each other while traversing obstacle 6, the first support protrusion 3152 can be located inside the adjacent insertion space 3154. This prevents the problem of the relative positions of adjacent unit blocks being restricted due to the overlap of adjacent support portions 3150. In other words, since the positions between adjacent unit blocks are not restricted by the support portions 3150, obstacle 6 can be effectively traversed regardless of whether the positions of the support portions 3150 overlap.

[0304] In the following text, refer again Figure 34 and Figure 35 The following describes the positional changes between adjacent unit blocks when wheel unit 10″ passes through obstacle 6.

[0305] Reference Figure 34 When wheel unit 10″ contacts obstacle 6, the support protrusion 3153 of any unit block 3100a first contacts the upper surface of obstacle 6. However, before contacting obstacle 6, as described above, adjacent unit blocks remain adhered to each other. At this time, the end 3143 of the fixing portion 3140 of the second unit block 3100b is spaced apart from the step portion 3119 of the first unit block 3100a by a predetermined distance.

[0306] like Figure 34 As shown, when the wheel unit 10″ rotates using the support protrusion 3153, which is in contact with the upper surface of the obstacle 6, as a fulcrum, a rotational torque is generated at the unit block 3100a that is connected to the support protrusion 3153. Therefore, relative rotational deformation occurs relative to the adjacent unit block 3100b, and the rotational deformation plays a role in inducing the aforementioned surface tension collapse.

[0307] Furthermore, typically when an external force is applied towards the hub of the wheel unit and exceeds a critical point that allows surface tension to collapse, the wheel unit may deform like an obstacle, but it is difficult to apply an external force exceeding this critical point to the wheel unit. Therefore, to address this problem, in this example embodiment, by applying torque to the unit block using a support protrusion, surface tension collapse can also be achieved using a smaller force than the external force in the direction towards the hub 3300. When the surface tension disappears through the above process, as... Figure 35 As shown, wheel unit 10″ can deform to conform to the surface shape of obstacle 6.

[0308] That is, when the wheel unit 10″ rotates, the unit block in contact with the obstacle 6 changes position, so that the support part 3150... The unit block, which is fixed to the edge of the obstacle 6 and located at the front end of the unit block in contact with the obstacle, moves forward due to the rotation of the wheel unit 10″. As a result, the distance between the support portions 3150 of the front unit block and the rear unit block decreases, and the distance between their fixing portions 3140 increases.

[0309] This is as referenced Figure 33 The description states that if the unit block includes a structure whose inner surfaces are separable from each other, then compressive force is applied to the outer surface and tensile force is applied to the inner surface. The tensile strain is not limited due to the separable structure and can increase indefinitely. That is, for adjacent unit blocks, compressive force is applied to the support portion 3150 corresponding to the outer surface to reduce the distance between adjacent support portions 3150, but the fixing portion 3140 corresponding to the inner surface is separable, and the tensile strain is unrestricted. Therefore, it causes... Figure 35 The segmentation state of the unit blocks shown allows for large deformations that match the shape of obstacle 6.

[0310] Therefore, for adjacent unit blocks, the fixing portion 3140 of the second unit block 3100b separates from the upper surface 3111 of the first unit block 3100a, the rear surface portion 3116 of the second unit block 3100b also separates from the front surface portion 3115 of the first unit block 3100a, and the protrusion 3130 of the second unit block 3100b also separates from the groove portion 3120 of the first unit block 3100a. Here, the degree of separation increases with the distance from the support portion 3150, and the degree of separation between the fixing portion 3140 of the second unit block 3100b and the upper surface 3111 of the first unit block 3100a is the greatest.

[0311] As described above, in contact portion A, since the inner surface of wheel unit 10″ includes a structure that can be divided from each other, the tensile strain is not limited by this division, thus inducing the effect of eliminating surface tension. Here, wheel unit 10″ rotates as a whole and moves forward when the surface tension collapses at contact portion A, so that wheel unit 10″ can effectively traverse obstacle 6.

[0312] In particular, in this embodiment, since the shape of the support portion 3150 can maintain a high supporting force on the edge of the obstacle 6, the supporting force between the contact portion A and the obstacle 6 is increased, and the wheel unit 10″ rotates and moves forward around the contact portion A. Therefore, the obstacle 6 can be climbed over more effectively.

[0313] In addition to the separation of the unit blocks 3100 that are in close contact with each other at contact portion A, the interior surfaces of the unit blocks 3100 located in adjacent portions B, i.e., those facing the hub portion 3300, are compressed and deformed against each other. Here, adjacent portions B can be defined as positions spaced a predetermined distance forward from contact portion A and positions spaced a predetermined distance backward from contact portion A. Here, when the interior of the unit block 3100 is compressed in adjacent portions B, due to the shape or structural characteristics of the unit blocks 3100, the separation or irregular positional changes of the unit blocks 3100 can be minimized.

[0314] In the following text, refer to Figure 36 and Figure 37 The deformation state of the unit block in adjacent part B is described. Figure 36 It is shown Figure 31 The front view of the changing state of the unit block at adjacent part B when the wheel unit traverses an obstacle, and Figure 37 It is shown Figure 36 3D images of the unit blocks from different perspectives.

[0315] Reference Figure 36 and Figure 37 In adjacent part B, the unit blocks that are adjacent to each other change, causing the outer support part 3150 to move away from each other due to tensile force, and causing the inner fixing part 3140 to move closer to each other due to compressive force.

[0316] However, in this embodiment, the fixing portion 3140 extends from the upper surface 3111 to form a stepped portion 3119. Therefore, the end portion 3143 of the fixing portion 3140 of the fourth unit block 3100d is located at the stepped portion 3119 of the third unit block 3100c, thereby restricting further movement of the end portion 3143 of the fourth unit block 3100d. Therefore, even if the interiors of the third unit block 3100c and the fourth unit block 3100d, which are adjacent to each other in adjacent portions B, are close to each other due to compressive force, the movement of the end portion 3143 of the fourth unit block 3100d is restricted by the stepped portion 3119 of the third unit block 3100c, thereby preventing them from being in close contact with each other to a certain extent and absorbing the applied compressive force.

[0317] In particular, such as Figure 34 As shown, the ends 3143 and steps 3119 of adjacent unit blocks are typically kept at a predetermined distance, thus ensuring that the compressive force at the adjacent part B can be compressed to a predetermined distance. Furthermore, even if the applied compressive force exceeds the predetermined distance, the convex shape of the end 3143 adheres to the concave shape of the adjacent step 3119, effectively absorbing a portion of the compressive force. Therefore, the unit block 3100 does not deviate from its position or irregularly change its relative position, and the overall shape of the wheel unit 10″ remains constant.

[0318] As described above, the unit blocks 3100 can be adhered to each other or freely separated, and can be designed to restrict changes in relative position, so that the overall shape of the wheel unit 10″ will not collapse and can very effectively traverse obstacles 6 such as stairs.

[0319] According to the embodiments of the present invention described above, based on the principle that water droplets maintain their appearance through surface tension, a force similar to the surface tension of water droplets is simulated by the tension applied by the support and the adhesive force between the unit blocks, so that the wheel unit maintains its overall shape and can effectively pass through the ground.

[0320] In addition, by applying the principle that the shape collapses when a force exceeding the critical deformation angle is applied to a water droplet, when the wheel unit comes into contact with an obstacle, the adhesive force between the internal unit blocks of the contact part is released and they are separated from each other, thereby effectively overcoming the obstacle.

[0321] Here, through the structure of the unit blocks and the tension after passing over obstacles, the collapsed parts can be easily restored to their original shape, thus maintaining the original shape of the wheel unit. Therefore, the wheel unit can smoothly traverse obstacles and travel on the ground.

[0322] In particular, each of the unit blocks can be supported at the edge of the obstacle by including a support portion. Therefore, the internal segmentation of the unit block can be effectively achieved. Furthermore, the first and second support protrusions are formed alternately to prevent adjacent supports from overlapping each other when traversing the obstacle, thus maintaining the structure while stably traversing the obstacle.

[0323] Furthermore, tensile strain is generated in the adjacent portions adjacent to the contact portion with the obstacle, causing the support portions of adjacent unit blocks to move away from each other. Here, the movement of the fixing portion is restricted by the step portion adjacent to the fixing portion, and the movement of the protrusion portion is also restricted by the groove portion adjacent to the protrusion portion. Therefore, when tensile strain is generated, the distance between unit blocks can be limited within a predetermined range, and a stable relative positional relationship can be maintained. Thus, when overcoming an obstacle, the structure of the wheel unit can be maintained in the adjacent portions.

[0324] That is, at the contact point where the obstacle is overcome, the interiors of adjacent unit blocks can be freely divided, and even if a predetermined tensile strain occurs in the adjacent parts, the relative positions of the interiors of adjacent unit blocks are restricted due to the fixed parts and protrusions. Therefore, the relative positions between unit blocks are naturally formed, and stable deformation of the wheel unit can be achieved.

[0325] As described above, the wheel unit 10″ according to the third embodiment may further include a tension control unit configured to control the tension applied by the support 3200. Here, the wheel unit 10″ may further include a rotation drive unit, a tension control unit, a distance holding unit, a distance changing unit, a rotation unit, and a controller, which serve as the tension control unit, wherein the first hub unit and the second hub unit, which are axially spaced apart from each other, may be configured as hub portions 3300. Therefore, since the distance between the first hub unit and the second hub unit can be adjusted, the tension applied by the support 3200 can be adjusted.

[0326] Figure 38 This is a front view showing a wheel unit for overcoming obstacles according to a fourth embodiment of the present invention. Except for the support body, the wheel unit of the fourth embodiment is substantially the same as the wheel unit 10″ of the third embodiment, and the same reference numerals are used for the same components and any repeated descriptions will be omitted.

[0327] Reference Figure 38 The wheel unit according to this embodiment is characterized in that a support 3201 is filled between the hub portion 3300 and the plurality of unit blocks 3100. Here, the support 3201 may be formed of a material with predetermined elasticity and filled between the hub portion 3300 and the plurality of unit blocks 3100, and the material of the support 3201 may be varied.

[0328] The shape of the wheel unit can be changed to overcome obstacles or various ground conditions, thus allowing external forces of various magnitudes, such as compressive or tensile forces, to be applied to the support 3201. Therefore, the support 3201 can absorb these applied external forces and change shape, then return to its original shape when the external forces are removed.

[0329] As described above regarding the support 3200, the support 3201 connects the hub portion 3300 to a plurality of unit blocks 3100 and provides tension between the hub portion 3300 and the unit blocks 3100. In this example embodiment, the support 3201 may be a filler material rather than a wire shape. As described above, the tension control unit can adjust the tension applied by the support 3201.

[0330] Furthermore, although not shown in the figure, the support 3201 can be filled between the hub portion 3300 and the plurality of unit blocks 3100, and is also connected to the lines described above.

[0331] Additionally, although not shown in the figure, a cover that surrounds the wheel unit as a whole may be provided in order to protect the wheel unit according to the embodiment.

[0332] Preferred embodiments of the present invention have been described above. Those skilled in the art should understand that various modifications and alterations can be made without departing from the spirit and scope of the invention as set forth in the appended claims.

[0333] Industrial applicability

[0334] This invention relates to a wheel unit for traversing obstacles, and more specifically, to a wheel unit comprising multiple unit blocks capable of relative rotation and movement between adjacent unit blocks by employing a deformation structure utilizing the surface tension mechanism of water droplets. Therefore, the wheel unit can not only travel on the ground but also easily traverse obstacles such as stairs, and particularly relates to a wheel unit for traversing obstacles that can achieve stable deformation when traversing obstacles.

Claims

1. A wheel unit, characterized in that, include: The hub rotates by receiving rotational force; Multiple unit blocks are spaced at a predetermined distance from the hub portion and form the shape of the wheel unit; as well as The support body is configured to connect between the hub portion and the plurality of unit blocks, or to fill the space between the hub portion and the plurality of unit blocks. When the wheel unit passes over a flat surface, the support body applies tension to the plurality of unit blocks in the direction toward the wheel hub, so that the plurality of unit blocks adhere to each other. When the wheel unit traverses an obstacle, adjacent unit blocks within the plurality of unit blocks rotate or move relative to each other. Specifically, when adjacent unit blocks rotate radially outward relative to each other, the adjacent unit blocks remain in an adhered state, and when adjacent unit blocks rotate radially inward relative to each other, the adhered state of the adjacent unit blocks is released and the distance between the adjacent unit blocks is increased.

2. The wheel unit according to claim 1, characterized in that, When the wheel unit traverses the obstacle, the adjacent unit blocks that are in contact with the obstacle rotate radially outward relative to each other, and at least a portion of the adjacent unit blocks that are not in contact with the obstacle rotate radially inward relative to each other.

3. The wheel unit according to claim 1, characterized in that, Each of the plurality of unit blocks includes: main body; A rotating part is provided on one side of the main body; A connecting portion is provided on the other side of the main body and rotatably engages with the rotating portion of the adjacent unit block; and A pin connects the connecting part and the rotating part of the adjacent unit block to allow it to rotate and move within a predetermined range.

4. The wheel unit according to claim 3, characterized in that, The subject includes: Inner surface, facing the hub portion; Outer surface, facing outwards; The contact surface extends in a concave shape between the inner surface and the outer surface; The end extends from the outer surface and protrudes from the outer end of the contact surface; and An inclined protrusion extends from the inner surface of the body toward the other side and protrudes obliquely in the direction toward the hub.

5. The wheel unit according to claim 4, characterized in that, Each of the plurality of unit blocks further includes a groove formed between the joint and the outer surface of the body. When adjacent unit blocks rotate radially outward relative to each other, with the joint of the adjacent unit block adhering to the contact surface of the main body of one unit block, the end of the main body of one unit block is inserted into the groove of the adjacent unit block.

6. The wheel unit according to claim 4, characterized in that, The rotating part includes a rotating block disposed at the contact surface of the main body and a protrusion extending radially inward from the rotating block. When adjacent unit blocks rotate radially inward relative to each other, the distance between the center points of the joint of each of the adjacent unit blocks increases, and the movement of the protrusion of the rotating part of one unit block is restricted by the inclined protrusion of the body of the other unit block.

7. The wheel unit according to claim 1, characterized in that, Each of the plurality of unit blocks includes: The main body forms an arc-shaped outer surface; and A connecting portion extends from the main body and forms an insertion space, into which the main body of an adjacent unit block is inserted. The connecting part includes: A first connecting surface extends from one side of the body; A second connecting surface extends from the other side of the body and forms the insertion space with the first connecting surface; and The contact surface connects the first connecting surface and the second connecting surface, and has a recessed arcuate surface to contact the outer surface of the body of the adjacent unit block.

8. The wheel unit according to claim 7, characterized in that, Each of the plurality of unit blocks further includes a recessed portion, the recessed portion being recessed between the body and the second connecting surface of the connecting portion. When adjacent unit blocks rotate radially outward relative to each other, with the contact surface of the connecting part of one unit block adhered to the body of the adjacent unit block, the second connecting surface of the connecting part of one unit block is inserted into the groove of the adjacent unit block.

9. The wheel unit according to claim 7, characterized in that, When adjacent unit blocks rotate radially inward relative to each other, the contact surface of the joint between the body of one unit block and the joint of the adjacent unit block is spaced apart and rotated, thus increasing the distance between the center points of the bodies of each of the adjacent unit blocks.

10. The wheel unit according to claim 1, further comprising: The elastic line is fixed and extended by a fixing portion formed on the side surface of each of the plurality of unit blocks, and is configured to apply an adhesive force between the plurality of unit blocks.

11. The wheel unit according to claim 1, characterized in that, When adjacent unit blocks rotate radially outward relative to each other and adjacent unit blocks rotate radially inward relative to each other, the adhesion state between the adjacent unit blocks is released, and the distance between the adjacent unit blocks is increased.

12. The wheel unit according to claim 11, characterized in that, Each of the plurality of unit blocks includes: The main body has a protruding front surface portion and a recessed rear surface portion that engages with the front surface portion of the adjacent unit block; A fixing part extends from the upper part of the main body; and A support portion protrudes from the lower part of the main body. The support portion includes: A support frame extends in a direction parallel to the lower part of the main body; and The support protrusion protrudes in a direction perpendicular to the support frame.

13. The wheel unit according to claim 12, characterized in that, The support protrusion of one unit block in an adjacent unit block is formed as a first support protrusion protruding from the center of the support frame, and the support protrusion of the other unit block is formed as a pair of second support protrusions protruding from both sides of the support frame to form an insertion space for inserting into the first support protrusion.

14. The wheel unit according to claim 12, characterized in that, When the wheel unit traverses the obstacle, the adjacent unit blocks that are in contact with the obstacle rotate radially outward relative to each other, such that the support protrusion contacts the obstacle and the main body is spaced apart from each other.

15. The wheel unit according to claim 12, characterized in that, The fixing part includes a contact surface and an end, the contact surface being configured to slide along the upper surface of the body of the adjacent unit block, and the end being formed at the end of the contact surface. The upper surface of the main body and the fixing part form a stepped part. When adjacent unit blocks rotate radially inward relative to each other, the movement of the end of the fixed part of one unit block is restricted by the stepped part of the adjacent unit block.

16. The wheel unit according to claim 12, characterized in that, Each of the plurality of unit blocks further includes: A recessed portion, formed to a predetermined length on the front surface of the main body; and A protrusion protrudes from the rear surface of the main body. When adjacent unit blocks rotate radially inward relative to each other, the movement of the protrusion of one unit block is restricted by the groove of the adjacent unit block.

17. The wheel unit according to claim 1, characterized in that, The hub portion includes a first hub unit and a second hub unit spaced apart from each other along the axial direction. The support structure includes multiple lines connecting the plurality of unit blocks to the first wheel hub unit and the second wheel hub unit. When the distance between the first hub unit and the second hub unit is adjusted, the tension applied by the plurality of lines is adjusted.

18. The wheel unit according to claim 17, characterized in that, Further includes: The rotary drive unit is configured to provide rotational force; A rotating unit is connected to the rotating drive unit and rotates; The tension control unit is configured to provide a sliding force along the said axial direction; as well as The distance adjustment unit is configured to provide the sliding force to at least one of the first hub unit and the second hub unit to adjust the distance between the first hub unit and the second hub unit. The first hub unit and the second hub unit are located on the outer surface of the rotating unit and rotate together.

19. The wheel unit according to claim 17, characterized in that, When the wheel unit passes over a flat surface, the distance between the first hub unit and the second hub unit increases, and the tension applied by the plurality of lines increases. When the wheel unit traverses an obstacle, the distance between the first wheel hub unit and the second wheel hub unit decreases, and the tension applied by the multiple lines decreases.

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